Again, not knowing much about the Kinetix unit;
An increase in resistance (on the output) will increase the load demand which the unit should respond with an increase in supplied current which will increase the voltage demand.
An example I currently have is via a PowerFlex 4m drive. I'm using it in a display for AF2018 and it's running a fan. The fan I was going to use apparently has a problem and it's measured resistance is high (compared to spec). The drive tried to start it but faults with an over voltage error. My understand of that error is that the current demand on the output is higher than the drive can supply.
To be fair I am guessing on your situation but it makes sense to me that if resetting connections has fixed similar issues before than resistance on the connections is the likely culprit. Besides, cleaning them can't hurt.
This is one of the first things I plan to check. I am still young at this and learning new things, but, honestly, I don't think I ever thought of this before, that extra high resistance in the connectors or motor could actually push a overvoltage fault. That is intriguing and something I will save in my bag for future reference! Thanks.