@MMRIZE Thanks for your work on this MMRIZE!

@schwarem , my temp solution was to use an older copy of the MMM-CalendarExt3Agenda config file I happened to have backed up.
For the sake of completeness (and those who may have to troubleshoot in the future) I just saw the notification of an update for the module today and installed it. Unfortunately, the module would not display at all. Luckily, I had also saved the module config file from when I initially had issues with the module updating (i.e. from a week ago when I first noticed issues). I replaced the very old module config file with this more recent config file and everything is working great!