Depending on the UCSM firmware version, you can re-ack the specific IOM and not the whole chassis.
If that doesn't resolve, I would open a TAC case.
There are logs in IOM (inside chassis tech support) that may help ID if this is an issue with IOM, and UCSM tech support will help ID if this is related to an issue with FI, etc.
I'm assuming the 'show int eth 1/14' on FI B nxos doesn't contain any considerable errors in counters?
What UCSM infrastructure firmware version are you running?
Kirk...