[Bug] Exercise 3 unavailable after Exercise 2 is completed AND completion green ticks are not displayed in "Слоги Королёвой Гласные А-И-У"

[HappyEgoiste]

Precondition:

1. Log in as default user ([email protected] / password)
2. Complete exercise 1 at https://brainup.site/groups/1/series/18/subgroup/142/exercise/1978 and press "Продолжить" button (refresh the page if needed to make Exercise 2 available)

Steps to reproduce:

1. Complete Exercise 2 at https://brainup.site/groups/1/series/18/subgroup/142/exercise/1979 and press "Продолжить" button

Actual result: Exercise 3 is not available to continue AND completion green ticks are not displayed. Refreshing the page does not make Exercise 3 available to the default user.

Comment: several page refreshes help from time to time, but not always. You have to complete previous exercise once again to open the next exercise.

Expected result: Exercise 3 is open for practicing AND green ticks mark completed exercises.