The kit scans the DIP switches on power up and does a self check to ensure they are set to be compatible with whatever board the kit is installed on, so either the DIP switch itself is intermittent, or there is an issue with the vintage hardware and/or it's interface creating an invalid return which "confuses" the kit into outputting a DIP setting for a different board.
That could still be related to the grounding issue, or voltage fluctuations from cold solder or a flaky power supply. Most likely it is not a kit issue; there are no known bugs or bug reports related to the DIP setting self-test routine.