Unable to connect to emissions test computers

My 2011 Prius has been unable to get through emissions testing at four different emissions sites now. It's a connection failure every single time. Sometimes it gets past one initial step but fails to connect later on and most times it doesn't connect at all (I've tried a few times at some of the sites). However my BAFX OBD reader works fine and so does the AutoZone one. There are no codes reported. I've checked the voltage and it's 12V on the OBD port, nothing weird there. Given the failures are only on emissions computers, I have no idea what I could reasonably check to try and resolve the issue. They're all using the same OBD port and using the same CAN bus.

I've had the car for years, it's never had an issue in the past with emissions testing. Not really sure what to try. I could hook a scope or logic analyzer to it if need be but frankly I can't think of any weird variation in protocol/timing that could suddenly pop up nor do I have any data on what it should be to compare against to determine if it even existed, so diving super deep into that doesn't seem helpful.

Any ideas at all?