Well, after my previous post it worked flawlessly until today (13 days), when it started acting up again. First time I restarted the tablet, second time I had to remove and re-insert the battery to get it working again. I refuse to believe that Microsoft is sending us ten year old batteries, mine is dated to 2018, if I'm reading the battery label correctly. I guess I'll call Microsoft and ask for a new pen.
Just posting update to add to the community knowledge base.