Unable to edit from timeline

I'm using VSCodium 1.88.1 and MarkWhen version 1.4.2

I'm unable to edit events from the timeline, for example:

• When in the timeline, I cannot grab an event for drag and drop.
• I am able to grab the ends to change the start/stop times individually, but the changes revert to the original as soon as I release the mouse button.
• I cannot add a new event from the timeline, nothing happens when in click the + button