Simple Text Events Choke Smooth Playback?

Hi there, I’ve been using Premiere for more than a decade, I’m in the middle of cutting a feature project I’ve been working on for more than 4 months with no issues at all, and I’m hitting a problem I’ve never seen before — it JUST started happening:

I’m putting in occasional simple text overlays using the Text tool to create a few subtitles here and there, no more than one line of text per event, default font. Media is 4K .mov H264 and has been running flawlessly with no trouble.

PROBLEM: On either side of the text event, for about a second on both sides, playback drops frames to the point of basically freezing, and then resumes normal smooth playback. It feels like the same thing that happens when the machine chokes on a large data file or a big FX render that it can’t handle in real time.

It’s one layer of media, no FX, and -- this happens even AFTER I RENDER and have a green bar. 

I’m doing some crazy compositing in other areas of the movie with multiple layers of media with moving mattes and stabilizations and color grading all rendering in real time, but for some reason these text boxes seem to be throwing Premiere for a loop.

I’ve tried deleting the render files and re-rendering.

I run the Progam monitor with 1/2 rez selected, but most of the time I get full rez playback. Tried 1/4, no change.

I’ve tried deleting them and re-creating them rather than copy and paste, same same.

I have restarted several times, and updated OS and Premiere so everything is up to date.

Anyone have any suggestions as to how I might fix this so playback is smooth? It’s really bumping me and I can’t figure it out.

MacBook Pro M3 Max 128GB OS14.6.1

Thank you!!!

Josh