Archie has suggested it so many times, use BasicLabel control for troubleshooting.
It is better than other controls because it can expand to show full errors (with AutoSize set to True and make sure nothing is close to it).
Just place it next to the control you are having issues with, use the same driver and point to the same PLC address (both PLCAddressValue and PLCAddressKeypad properties).
Also, try to provide Wireshark capture as well.
