Coldcard can sign base64 PSBT in multi-sig but not the Coldcard specific one (unique derivation path)

I created a 2-2 multisig with a Cobo (1c358993) and a Coldcard (0c1ca269). For the Coldcard, I picked an interesting derivation path: m/49h/0h/6940h

I set up my first PSBT, I was able to sign with the Cobo but when I sign with the Coldcard I get this error:

I imported the multisig file manually and allowed it to import from the psbt and got the same error. I tried both airgapped and via usb and got the same error.

When I exported the base64 PSBT, the Coldcard is able to sign the transaction with no issue.