First are you using a RPi CM5-2712 or a Radxa CM5-RK3588S big difference on what it could be. If it’s the RPi CM5 then when you had it booted the first time you needed to edit the EEPROM to the settings outlined here. It’s the first thing you should do next time you get it booted.
To try and get it working again, remove the batteries it makes shutting down a failed boot easier. You cannot shut the device down by the power button on a failed boot. You need to just pull power. Try smaller SD cards and a few different ones. Once you apply the EEPROM settings change then any SD card will work.