2021 MacBook Pro not reading CFx card reader

ANEJIP wrote:

I plug my card reader into my 2019 MacBook Pro and have no trouble at all, I plug it into my 2021 MacBook Pro and it won't show up. Any ideas??

What about the built in card reader on the 2021 14" /16" MBP(?)

Show up where?

make changes to your Finder>Preferences> Sidebar

make changes to your Finder>Preferences>General>Desktop

is there an adapter involved(?) verify Apple® branded: USB-C to USB Adapter - Apple

About the SD and SDXC card slot on your Mac - Apple Support

ANEJIP wrote:

It doesn’t show up in disk utility, desktop or finder and I’ve already make sure those settings were correct. I plug it in on my 2019 and it pops right up on finder, just doesn’t show up on the 2021.

You do not mention a brand name— have you searched for any software/driver updates for compatibility?

I have this exact problem too. I have tried using different cfexpress card readers and both light up when plugged in but they are not recognized by Bridge, finder, etc. Both readers and this card are immediately recognized by my 2019 MacBook. I have confirmed preferences and all are checked. My external hard hard drive from OWC is immediately recognized.

I finally solved when I operated to the most current version of Monterey 12.0.1. Must have been a bug in prior version as nothing else worked.