Cursor not always visible on dark theme

Cursor often not visible with a dark mode theme (i've tried several). I'm using firefox. I can usually make it come back back performing some right click action, such as describe. Changing the theme does not make the cursor come back. The cursor is "working" - as when I type it is inserting where i clicked. I just can't see it. But, when this is happening, I also can't navigate using the arrow keys. The cursor says where the mouse put it. This seems to be the case when I reload a project and come back for its existing documents. If I add a new document it has a cursor. If I copy a document - it sometimes doesn't. I can't figure out exactly how to reproduce this, but it seems to happen more often than not.