Black Thumbnails in Premiere Pro After Linking Proxies (Sony FX30)

Hi everyone,

I’m having an issue with Adobe Premiere Pro after linking proxy files created from my Sony FX30 footage. Once I attach the proxies, the thumbnails in the Project panel turn completely black.
However, when I hover the mouse over them, the preview appears.

This problem started about a month ago — before that, everything worked fine.

What I’ve tried so far:

Uninstalled and reinstalled Premiere Pro

Cleared all Media Cache files

Checked different project settings

My system:

AMD Ryzen 5 5600

Sapphire RX580 4GB

48GB RAM

I don’t think it’s a hardware issue since the exact same setup used to work without problems.
I’m attaching a screenshot for reference.

Has anyone experienced this issue or found a solution?

Thanks in advance!