Did you add record config?
https://docs.frigate.video/configuration/record
The errors maybe are related with ffmpeg configurations, please ask for help on github https://github.com/blakeblackshear/frigate
Not sure if it is going to work but you can try with one like this: https://www.amazon.com/-/es/Adaptador-RIITOP-tarjeta-lector-compatible/dp/B08FWZXT2N/ref=sr_1_3?keywords=usb+to+m2+adapter&qid=1651043207&sr=8-3
Some time ago @ich777 said this, maybe is useful for you.
You have to change the auth mode to "Both plain and digest" under Configuration > General > Base switching to expert mode:
I opened an issue related to this:
https://github.com/jfarseneau/antennas/issues/85
Yes, in M.2 devices you only need to install the drivers, but @ich777 can confirm this as I don't own an PCI-M2 device.
There have been USB failed devices too, is just a lottery.
Can you show device list? Some people made the mistake of binding the device to VFIO-PCI
Can you see the coral in the device list of unraid? If you can and your are pointing to it in the frigate container as it looks like you are doing it right, It can be a failed coral. There have been more cases in the past in this forum...