Pen tool stuck on add vertex

My pen tool is stuck on add vertex. I can change it to remove vertex, but not the default pen option or convert vertex, or mask feather. This was happening in 23.2. I updated to 25.1 but the problem persists.

I have tried the fix detailed in an old post relating to the same problem in version 16.1.3 - https://community.adobe.com/t5/after-effects-discussions/the-pen-tool-is-stuck-on-add-vertex-tool-in-ae-16-1-3-build-5/m-p/10618330#M92310 - but this has not worked.

Grateful for any solution - this is a pretty serious problem for the paricular work I need to do.