Adobe Premiere Pro SUPER SLOW on a Mac Pro

I'm having a bit of an issue with Adobe Premiere Pro, and I could really some help to sort it out.

Here's what I'm working with:

• Mac Pro 3.2 GHz 16-Core Intel Xeon W
• 96 GB Memory (RAM)

• AMD Radeon PRO W6800X 32 GB (Graphics)

• 2 TB Internal Storage
• LaCie 28 TB External Hard Drive
• Adobe Premiere Pro [Version 23.6]

So, I was working away in Adobe Premiere Pro, editing my project on my LaCie drive. Everything was going smoothly. But the software suddenly got super slow. Clicks and commands? Taking forever. The timeline? Crawling. Editing? A real struggle.

Now, the odd part is that playback is totally fine. No issues there. Just the rest of the software seems to have gone on vacation.

I tried a bunch of stuff:

1. Restarted both my computer and Premiere Pro.
2. Made sure everything's up to date.
3. Emptied out the cache to free up space.
4. Gave preferences a reset and restarted.
5.  Re-attached the proxies to make sure everything is connected.

But no dice. I'm baffled. Adobe Premiere Pro is my work essential, and this slowdown is like a roadblock.

Any advice?