Sometimes the seek bar and other controls become inoperable

[umlx5h]

Sometimes the seek bar and other UI controls does not appear or cannot be operated.
I have confirmed that this can occur when used after being left idle.

It's difficult to investigate because it is difficult to reproduce.

[Current Workaround]
Changing window size or Toggling the fullscreen (press F key twice) will fix it.

[gulgamgug]

It is not consistent.. sometimes 15m of being idle the bug happens, and sometimes its 1hr

[umlx5h]

The only relevant modifications on the Flyleaf library are the following, so the cause may be on the library.
b26a777

I'll check if this is reproduced with a minimal sample.