There's no reason at all - unless you've got some links - to suspect that the information I relayed isn't the actual reason... that in Canada, 40A circuits are common on NEMA 14-50 outlets and 80% of 40 = 32A is the reason we're restricted to 32A. Nothing to do with 70% for "continuous loads" (70% * 50 = 35, not 32 and Telsa engineers are perfectly adept at arithmetic) and nothing to do with fancy Canadian electrons that are hotter than American ones.
I don't believe I said anything about 70%. In the US and Canada, it is permissible to install a NEMA 14-50 on a 40 amp circuit which, by both US and Canadian code limits "continuous loads" to 80% of that rating. "Continuous loads" are defined in US and Canadian codes and include EV charging. I have relatives in the US with electric stoves hooked up the same way we do here in Canada (on 14-50's with 40 amp breakers). But they are no more or less common in either country since both the NEC and CEC allow this configuration.
As I said, it came down to a certification issue in Ontario. The original UMCs were not CSA or UL-C listed. Now they are. It was a condition of the testing and listing that resulted in this requirement.
I suggest you refer to Section 86 of the Ontario Electricity Safety Code for further information on electric vehicle charging systems.
Then I suspect you have a specific defect somewhere unrelated to any of this.
The magic comes down to a resistor on the pilot pin.. that's all. The car controls the charge rate, but it does this based on the "signal" it receives by way of measuring that resistor. New Canadian adapters "tell" it to charge at 32A while American ones "tell" it to charge at 40A.
It seems odd then that Tesla would have gone to the expense of sending me a whole new UMC set and new adapter. Prior to this, there were some overheating situations that led to a recall of the original 40 amp adapter. Then, they just sent me a new 40 amp adapter that had a thermal fuse in it, not a whole new cable set. I checked again, and my original and updated 40 amp adapters will not work on the new UMC that Tesla sent me. They both still work on the old UMC cable.
For me, this all transpired a few years ago. Maybe "newer" UMCs are able to recognize both 40 and 32 amp adapters by their internal resistors.