There are known problems in Mac OS 13 importing from Nikons and some other cameras via a USB cable. On some cameras, you can work around this by enabling mass-storage mode. The other known workarounds are to use Mac's Image Capture to copy the photos to disk and then import to LR from there, or to use a card reader. (In general, card readers are significantly faster than importing via cable.)
I looked at the Canon R5 manual and it doesn't appear to support USB Mass Storage mode (accessing the camera's memory card like any USB drive via the USB cable). Some googling indicates that Canon hasn't supported Mass Storage mode for a long time, if ever.
That's too bad, because that appears to be an easy workaround for the Mac OS 13/LR problem.
So you'll have to use a card reader, Mac's Image Capture, or the Canon EOS Utility.