Same here, I too am a US customer on Mint Mobile. I have been using my Kompakt daily ever since I first received it at the beginning of September and I have never had a single issue with its phone functionality whatsoever. For me it works and has always worked as a phone. I don’t know what it is, but I have seen several posts on the forum of people having issues with its basic phone functionality, and that just has not been my experience at all. Is it the carrier? I don’t know what it is that is causing people to have issues with the phone functionality part.
I won’t say the Kompakt doesn’t have its shortcomings though. In fact I made a whole post detailing everything I would like to see included in future updates. I also agree that Mudita’s working pace is slow as molasses , but I’m confused about the claims I’ve seen that the phone doesn’t even work as a phone. I guess I should consider myself fortunate that I haven’t had any issues.