Extension mouseover strange behaviour in AE 17.1.4+

Hello,

I have a relatively simple extension that will play the piece of footage you mouseover, in a bigger preview window. This is done with a mouseover eventListener, which loads and plays the proper video on mouseover, and removes on mouseout.

I have tested on all AE CC 2020 versions, and found that this normal mouseover behaviour works perfectly fine in all versions until v17.1.4 and above. The only way I have found to fix it, is to click somewhere in the extension.

Any ideas why this might be happening only in the newest few versions of AE?

-Nate