I have done a fresh new install of 8.1 and new to plexguide however I noticed portainer is not auto installed is part of the core apps list and after you install it it starts the contianer with cmd "- -no-auth" (according to portainer) which would explain for the no login prompt.
So this maybe a noob question but how do I go about protecting portainer in this instance?
thanks guys fixed. I restored the password and put portioner back, it got sucked into core apps, so when it started, it had no way to start portioner. I put a copy of it in the main pg for the initial auto creation. please report new thread if issue persists!