When I trim a clip on the timeline and delete the unwanted bit, the remaining part of the clip goes blank

This relates to Premiere Beta.

I have recently worked out how to apply colour correction to multiple clips at the same time (74 clips on my current timeline).

Once I have done this, when I change from Colour to Edit, it takes several seconds before the screen responds. Also, when trying to colour grade, I move the cursor, but it takes several seconds for the screen to react (it is usually instant).

Then, when I trim a clip and delete the unwanted part, the remaining bit of the clip appears blank in the timeline. If I save and close the project and then reopen it, the clip appears, but the issue reoccurs as I contine to trim clips.

Windows 11 26H2

Premiere 27.1.0 Beta, build 31

Nvidia GeForce RTX 4090 version 610.88