I feel bad for the originator of Mlem, honestly. Why in the world would someone download a beta app and then throw a fit when something doesn’t work quite right? My goodness, it’s in TestFlight, it’s not a release candidate yet and there is going to be some unexpected behavior sometimes.
My personal preference for apps is Memmy (and I’ve tried all of the ones currently in beta) but I’m not sending nastygrams to the other devs because they didn’t fit my taste preferences or they crashed or something.