Missing bookmarks tracking issue
(Note : please have a header on your comments describing which scenario you are describing ex: " "pre-sync simple case laptop-laptop")
Pre-sync import scenario
simple case ( < 50 bookmarks )
- [x] laptop - laptop scenario
- [x] laptop - iOS scenario
- [x] laptop - android scenario
complex case ( > 6000 bookmarks, nested folders )
- [x] laptop - laptop scenario
- [x] laptop - iOS scenario
- [x] laptop - android scenario
Post-sync import scenario
simple case ( < 50 bookmarks )
- [x] laptop - laptop scenario
- [x] laptop - iOS scenario
- [x] laptop - android scenario
complex case ( > 6000 bookmarks, nested folders )
- [x] laptop - laptop scenario
- [x] laptop - iOS scenario
- [x] laptop - android scenario
Post-Sync Import Scenario - Complex (1500 bookmarks with nested folders) - laptop to android:
all 1500 bookmarks synced to android. I then added an iOS device (iPhone) to the sync group once sync on Android was complete. As of now, iPhone only has approximately 400 bookmarks. Additionally, if you switch the order (add iOS to sync group, then Android), Android still gets all 1500 bookmarks synced, whereas iOS still only gets approx 400.
Post-sync import laptop - iOS scenario (complex case)
laptop version : 0.18.5 iOS version : 1.4 (17.07.13.15) created sync group on laptop, joined iPad attempted to import with laptop and iOS app open brave_sorted_ish.html.zip
multiple errors on sync console, many thousands of bookmarks missing

Pre-sync import laptop - iOS scenario (complex case)
laptop version : 7b31653eb555ba8f00395cd593f9b948ada296fe iOS version : 1.4 (17.07.13.15) created sync group on laptop, joined iPad attempted to import with laptop and iOS app open brave_sorted_ish.html.zip
No errors on laptop sync console.
While it cannot be conclusively proven, it appears as though the bookmarks have all synced to the iOS device. However the order is not consistent.
vs
Post-sync import laptop - iOS scenario (simple case)
laptop version : 7b31653eb555ba8f00395cd593f9b948ada296fe iOS version : 1.4 (17.07.13.15) created sync group on laptop, joined iPad attempted to import with laptop and iOS app open brave_sorted_simple.html.zip
No errors on sync console.
All bookmarks appeard on iOS, but the order wasn't maintained.
Pre-sync import laptop - iOS scenario (simple case)
laptop version : 7b31653eb555ba8f00395cd593f9b948ada296fe iOS version : 1.4 (17.07.13.15) created sync group on laptop, joined iPad attempted to import with laptop and iOS app open brave_sorted_simple.html.zip
No errors on sync console.
All bookmarks appeard on iOS, but the order wasn't maintained.
It should be noted that iOS order was different from the Post-sync simple case. From this, I would intuit that either the order in which iOS is pulling sync records is random or the order in which the records are being added to the sync group is random.
Pre-Sync Import Laptop-Android scenario (simple case)
Laptop version: 0.17.17 (dbc3c4d96029de2eb64735d31c0067ae0b6f878a) Android version 1.0.25 Created sync group on laptop, imported 49 bookmarks (see brave_sorted_simple.html.zip from comment above), joined sync group on Android. No errors on sync console. All bookmarks appeared on Android, order was maintained.
Pre-Sync import Laptop-Laptop scenario (complex case)
Laptop Pyramid 0 : https://github.com/brave/browser-laptop/commit/e4e0cec453dab14f1b981800fd5f3b7b9ce0c772 (Ubuntu 16.04) Laptop Pyramid 1 : https://github.com/brave/browser-laptop/pull/9988/commits/7b31653eb555ba8f00395cd593f9b948ada296fe (Windows 10 x64)
Import 5k bookmarks file on Pyramid 1
Enable Sync on Pyramid 0
Sync with Pyramid 1 using keywords
No errors on Sync console
All bookmarks appeared on Pyramid 0
Bookmark structure maintained as it is
19_07_2017.zip

Post-Sync import Laptop-Laptop scenario (complex case)
Laptop Pyramid 0 : brave/browser-laptop@7b31653 (Windows 10 x64) Laptop Pyramid 1 : brave/browser-laptop@e4e0cec (Ubuntu 16.04)
Enable Sync on Pyramid 0
Sync Pyramid 1 with Pyramid 0 using sync code
No errors on Sync console
All bookmarks appeared on Pyramid 1
Bookmark structure maintained as it is

Pre-Sync import Laptop-Laptop scenario (simple case) - ~300 Bookmarks
Laptop Pyramid 0 : brave/browser-laptop@7b31653 (Windows 10 x64) Laptop Pyramid 1 : brave/browser-laptop@e4e0cec (Ubuntu 16.04)
Import bookmarks file with ~300 bookmarks on Pyramid 0
Enable Sync on Pyramid 0
Sync with Pyramid 1 using keywords
No errors on Sync console
All bookmarks appeared on Pyramid 0
Bookmark structure maintained as it is

Post-Sync import Laptop-Laptop scenario (simple case) - ~300 Bookmarks
Laptop Pyramid 0 : brave/browser-laptop@7b31653 (Windows 10 x64) Laptop Pyramid 1 : brave/browser-laptop@e4e0cec (Ubuntu 16.04)
Enable Sync on Pyramid 0
Sync with Pyramid 1 using keywords
Import bookmarks file with ~300 bookmarks on Pyramid 0
No errors on Sync console
All bookmarks appeared on Pyramid 0
Bookmark structure maintained as it is

Post-Sync import Laptop-Laptop scenario (complex case)
Laptop Pyramid 0 : brave/browser-laptop@e4e0cec (MacOS) Laptop Pyramid 1 : brave/browser-laptop@e4e0cec (Linux - Ubuntu)
Enable Sync on Pyramid 0 Sync Pyramid 1 with Pyramid 0 using sync code Import 6000+ bookmarks on Pyramid 0, Pyramid 1 was left open No errors on Sync console Not all bookmarks were synced to Pyramid 1 Some folders missing on Pyramid 1 also.
numbered_bookmark_file.html.zip
In screenshot Pyramid 1 is on the left, Pyramid 0 is on the right.

Pre-sync import scenario - Laptop-Android - Complex case ( >6000 bookmarks, nested folders)
Pyramid 0 - MacOS (0.18.10) Pyramid 1 - Android (Nexus Galaxy S4) Imported > 6k bookmarks with nested folders. Enabled sync on laptop. Joined sync group on Android. All bookmarks synced to Android.
Post Sync Scenario - Complex Case (>6k bookmarks, nested folders)
Pyramid 0 - iPhone 7+ (iOS 10.3.3) Beta ver 1.4(17.07.20.16)
Pyramid 1 - Laptop Windows 10 x64 (https://github.com/brave/browser-laptop/commit/7b31653)
Enable Sync on iPhone -> Get sync code
Add laptop to sync group using the code words from iPhone
Import >6K bookmarks file on Laptop
Bookmarks failed to show up on iOS due to https://github.com/brave/browser-ios/issues/983
Kill and restart app, bookmarks synced
Last nested folder is not shown on top but somewhere in between bookmarks

Post-sync import scenario - Laptop-Android - Simple case ( <50 bookmarks)
Pyramid 0 - MacOS (0.18.10) Pyramid 1 - Android (Nexus Galaxy S4) Enabled sync on laptop. Joined sync group on Android. Imported less than 50 bookmarks. All bookmarks synced to Android.
Post-sync import scenario - Laptop-Android- Complex case ( >6000 bookmarks, nested folders)
Pyramid 0 - MacOS (0.18.10) Pyramid 1 - Android (Nexus Galaxy S4) Enabled sync on laptop. Joined sync group on Android. Imported > 6k bookmarks with nested folders. All bookmarks synced to Android.
Post Sync Scenario - Laptop-iOS - Complex Case (>6k bookmarks, nested folders)
Pyramid 0 - MacOS (0.18.10, 73465bb) Pyramid 1 - iPad (iOS 10.3.1) Beta ver 1.4(17.07.20.16) Enable Sync on Laptop -> Get sync code Add iPad to sync group using QR Code. Import >6K bookmarks file on Laptop from Firefox. Bookmarks failed to show up on iOS due to brave/browser-ios#983 Kill and restart app, bookmarks synced Last nested folder is not shown on top but somewhere in between bookmarks
Confirmed findings from @srirambv in https://github.com/brave/sync/issues/146#issuecomment-317507040