The point for my OP was to see whether the previous Kobo ereader generation (Libra, Clara HD) were possible affected by a bad batch of micro-USB female connectors, or not.
As all the current replies are just concerned with (greatly appreciated!) aiding my connection habits for the better, I assume this phenomenon is indeed just me and I was just unlucky to have encountered twice some device which, I guess, was crafted on a blue Monday morning
It happens.