I don’t have any other suggestions. 99% of the time when values are not updating it is a symptom of the php setting max_input_vars not being set high enough.
max_input_nesting_level can also be an issue if you have repeaters that are deeply nested, but this is rare.
There may also be other server settings that also deal with these dependent on your hosting environment, but I don’t know the specifics of these.
There have also been reports in the past of issues with caching of different types that cache admin values, but this should also be rare.
Unfortunately, beyond this there isn’t much I can do to help you other than the basic “deactivate other plugins” and “try a different theme” to see if you can locate a conflict of some kind.
