deathiningly slow insert from source monitor into timeline | playback image on screen black

This occures on clips / in timelines that have both transcripts and captions on them and seems to be an issue for a few itterations of the beta now. I've had instances where i've had to wait a minute or two for the insert to take place.

This translates to sluggish timeline response time and slow very sluggish edit response times. 

to clarify - the action is as follow.

I have a 'stacked' or dalies timeline loaded into my source monitor with sync'd multiclips inside it. The audio on the multiclips have been transcribed and we have had to add captions into our stacked timeline corrusponding with our multiclips (as the interviews are in a different language and transcripts don't do translations yet ( **Feature request** )

I've also had issues when the captions are on where the video from my video tracks doesn't show up and all i get is a black screen. this tends to get resolved when I toggle the track output off and on again (or sometimes go into the multiclip to do it)

Windows 11 

i9-9900K CPU @ 3.60GHz 3.60 GHz
Installed RAM 32.0 GB
Premiere BETA 23.6.0 (build 15)

Nvidia Geforce RTX2070

Thanks!

E