Hello!
I'm having an issue where the rig moves back to an old pose when moving a few frames forward despite setting keyframes the bones. It seems to happen each time I set a key. I can use the rig just fine other than that. It's specifically the legs that move to a different position. While I'd rather keep working in 2.92, is it a better idea to DL a previous version of Blender?
Take a look at the other Foot.
In those images you have the right foot selected and there is only a keyframe on F01.
It looks like the issue is with the left foot. When you select that, you will see the keys in the timeline.
I can also see that you have auto keying enabled but just double check what keying set you are using. It may only be setting keys on some channels and not all the channels you want.
Hope that helps.