Paste not immediately available cross dynamic-project

Windows 10, 17.0... With dynamic project switching on, two projects open, and in the Edit page on project1, I place the timeline where I intend to paste-insert some objects to be copied from project2. I use the top dropdown to switch to project2, select the desired objects and choose Edit/Copy. I use the top dropdown to switch back to project1, and immediately try to Paste (and Paste-Insert) are not available.
Usually I just press the keyboard shortcut, and in the past I was simply surprised that nothing pastes, and go back to project1 to try copying again.
However, I found that if I drag the timeline slightly back and forth (while in project1), suddenly paste and paste-insert become available. That seems a bug.
Usually I just press the keyboard shortcut, and in the past I was simply surprised that nothing pastes, and go back to project1 to try copying again.
However, I found that if I drag the timeline slightly back and forth (while in project1), suddenly paste and paste-insert become available. That seems a bug.