V21.0 Video player controls do not show

I run Kodi 21.0 on a ChromeCast with Android TV 12 kernel v. 4.9.269

I use it to access a collection of video files (mostly .avi and .mkv) on a DLNA server on the home network.

When playing back some of the files (couldn’t identify a pattern, sorry) the video controls do not appear; I only have the square «Stop» control and the pan bar doesn’t work.

With other files the video controls appear (pause, back, fwd) and I can pan forward and backward along the video.

I have searched for solutions and tried some – no luck.

Any suggestions?