Restrict access of activity using User Profile field doesn't work/get updated when the Admin user changes the User Profile field, it seems it only works when the user logs out or update his profile himself.
Basically, if Admin user changes a student profile field which is used to restrict an activity access the update doesn't take effect, at least until the student user updates his profile or logs out.
How to replicate the issue with an example:
Admin user: admin
Student user: John
User Profile custom field: Subscription = Active / Inactive (Dropdown)
Activity: Lesson 1
John > User Profile > Subscription = Active
"Lesson 1" activity > Restrict access is set to > "User profile field" "Subscription" is equal to "Active"
Result: "Lesson 1" is available for John
Now Admin user changes John profile field > Subscription = Inactive
Result: "Lesson 1" still available for John when it should be Hidden
If the user (John) logs out and log in again or he updates his profile himself "Lesson 1" becomes hidden again