Switchport entering err-disabled state at a remote site as a result of BPDU Guard, and I can't replicate this in a lab environment. Any thoughts?

Hi all, I have been having an issue for the past couple of months now at a few remote sites. At these sites we actually run on switching hardware owned by another entity and they have port security and BPDU guard enabled on the access ports. Connected to these ports I have small receipt printers, and from there a USB cable from the receipt printer to a tablet. The printer uses SteadyLAN to pass off an IP connection to the tablet to also provide it internet as well, so essentially the client ends up seeing the MAC address of the tablet as well as the printer on their switch. This usually triggers their port security alerts for too many MAC's, but once we get past that they seem trigger BPDU Guard on the switching and the switchport goes err-disabled.

I reached out to the vendor of the printer and they are confident that their printer does not generate or understand BPDU's, and I happen to believe them as I tried to replicate in a lab environment at home using the same model printer and tablet, albeit different switching vendor and model to no avail. When I run a packet capture on the access port on the switch the only STP information I can see is all sourced from the switch, I see nothing STP-related sourced from the printer.

Anyone have any suggestion on what else I could try to help troubleshoot further? All suggestions are appreciated. :)