Priority setting

I’ve played around with the Priority setting in the configuration.
There are 3 options, but only two are permanently saved. The High setting goes back to Low after save.
BTW. which one you recommend? I’ve issues: non delivered messages sometimes.
Maybe because I enabled Message Carbons AND Forward Messages. Now I disabled the later one.
I’m using Conversations or Pidgin sometimes. Conversations is getting the chat messages always, but Converse.js doesn’t.