I gave a 7.3" one as a gift recently. Looking back I was brave and used inky_frame-v1.23.0-1-pimoroni-micropython.uf2 on it. It worked ok, I tested it by skipping through 15 images and I think I accidentally left it on overnight and it was ok and had auto-advanced. It’s far far away in the southern hemisphere now!
If you’re in thonny this implies you’re running on USB power so that rules out low battery issues. When it gets stuck can you interrupt it with Ctrl-C in the Shell window (REPL)?
Is the image one that has successfully shown before on an Inky Frame?
I think when I tried a Kingston micro SD card it failed immediately with a mount error. I’ve been using either ones from the kit or SanDisk 32GB ones since. They need to be 32GB or smaller.
Actually this problem was attributed in the end to what sounds like a partially incompatible micro SD card: Problems with jpegdec on inky frame 7