I can't copy/cut and paste because the text will not highlight

First thing: restart your mac. If the problem persists, restart in Safe Mode (How to use safe mode on your Mac - Apple Support). Test whether copy/cut/paste work in that mode. If yes, restart in normal mode. If not contact Apple Support: Get Support

This happens because you didn’t highlight it.

did you hihlighted the text?

try highlighting it here below. Then screenshot,

This is the testing to solve the problem.