[Issue]: Sampler settings are not saved from the UI

[lbeltrame]

Issue Description

Sampler settings such as scheduler_sigma, schedulers_beta_schedule, and so on (basically all sampler settings from the UI) are not saved correctly from the UI. When setting them and saving the configuration, the UI reports a change, and even modifies the config.json file, but the actual settings are not saved. This occurs with both the standard and modern UI, but does not occur when using the API. Every other setting is saved correctly, so I ruled out permissions, etc.

This was confirmed by using SD_CONFIG_DEBUG: the change is actually not saved (no changes are reported, despite the UI saying the contrary).

Steps to reproduce

1. Open the UI
2. Locate the sampler options (txt2img)
3. Change the sigma from the existing value to another (e.g. karras -> betas)
4. Go to the settings, hit save

Expected results

The config should be saved to disk

Actual results

Whatever was before in the settings is kept. If the change instead was from the API, it is (correctly, because the UI says otherwise) reset to whatever was in the UI.

Version Platform Description

08:19:09-704243 INFO Starting SD.Next
08:19:09-705833 INFO Logger: file="/home/lb/Coding/automatic/sdnext.log" level=INFO host="leon.private.heavensinferno.net" size=12688802 mode=append
08:19:09-706432 INFO Python: version=3.12.3 platform=Linux bin="/home/lb/Coding/automatic/venv/bin/python3" venv="/home/lb/Coding/automatic/venv"
08:19:09-721125 INFO Version: app=sd.next updated=2025-05-11 hash=0673689d branch=dev url=https://github.com/vladmandic/automatic/tree/dev ui=dev

Relevant log output

Backend

Diffusers

Compute

AMD ROCm

UI

ModernUI

Branch

Dev

Model

StableDiffusion XL

Acknowledgements

• [x] I have read the above and searched for existing issues
• [x] I confirm that this is classified correctly and its not an extension issue

[vladmandic]

i tried with standard and modernui and sampler settings seems to be correctly saved to config.json immediately upon a change via ui (as in immediately upon ui change, there is no explict save operation required).

11:10:06-507997 DEBUG    Sampler set options: sigma=betas
11:10:06-508841 TRACE    Settings set: schedulers_sigma=betas
11:10:06-528688 TRACE    Settings changed: schedulers_sigma=betas default=default

grep scheduler config.json

  "schedulers_sigma": "betas",

can you walk me through the exact step-by-step?

[vladmandic]

any updates?

[lbeltrame]

I haven't been really using the UI anymore, relying only on the API nowadays, so I can't tell at this point. I'll close for now, and reopen if I find a minimal working example.