[jamiet3333]'s is the quickest workaround by far. This is really irritating and a fairly recent bug. If Wyze isn’t monitoring this forum, do we all need to start emailing support with bug reports?
This particular problem isn’t with microSD cards or routers; it is a regression in the android app.
Basically, if you look at any point in the playback timeline that does not have video, the recording window is replaced with a screen shot of the last live image (same as the thumbnail for the camera on the main screen). When you move to a spot on the timeline that has video, the video starts playing (the traffic counter in the upper-left shows “KB/s” activity and the red line moves through the timeline. You can even hear the sound, if you are recording that.
It seems like the thumbnail never gets cleared from in front of the video and that is what appears to make it look stuck.