I have the same problem with pixel 3a.
It has blank space on bottom of the screen.
Use Simple Gallery Pro: Photo Manager & Editor from playstore(paid) or f-droid(free) which is an open source application.
Thanks, I will use the version you suggested, are you using default settings or you changed some?
Ok I'm sharing some screenshot of GCam setting.
Instagram vedios are not playing???
In settings, "Off" start video directly with sound option. Then try.