Console type is Nintendo Switch, playing season character (necromancer). 2 things appear to be odd, first when this issue occurs my inventory is showing items (equipped) on the left side of inventory but not showing any unidentified items even though the green star is over the category.
A workaround seems to be going to town opening the stash and start the process to transfer one or more items, close the stash and inventory goes back to normal for an unspecified period of time.
I can provide a screenshot if required.
Also can test on Mac, and Xbox if asked.
Let me know if any assistance is required, fellow product manager here, glad to help.