Mini sent their weekly email, which basically said that if your car does not keep charging just wait and it will restart by itself.
I doubted this in a reply to their email but I don't expect them to answer.
And I had the issue again tonight. I waited as they said. 30 minutes and it did NOT restart. I pulled out the plug and stuck it back in and all is well.
It is increasingly clear that my issue is time between turning off the car and starting to charge. It is not (in my case anyway) low voltage from the power company. When I plugged in tonight the car started blinking as it does when charging and then stopped after a few seconds. Both power phases were slightly above 125 volts and within 0.2 volts of each other, so that is not the issue as Mini suggested in their last mass email.
For over a week I made a point of plugging in the car the moment I turned it off and had no trouble with charging. Today I went back to taking my notes before plugging in which means several minutes wait after turning off and before charging, and the problem returned.
I will start timing how long of a delay from power off until plugging in a then log whether there is an issue with charging. This should give Mini enough info to reproduce the issue. In any case waiting does get around the problem but not without intervention. I do need to remove and replace the connector.
3 hours ago