Every time a companion agrees to come with me, they just walk away immediately after the dialogue, and off into the distance, forever, or at least I assume what will be until they hit the edge of the map...

Companions also disappear after I fast travel.

I Also cannot get a dialogue with Dogemeat. I hit A and all I get is my guy saying "Hey Boy" or "Come here Dogmeat" no other options to do anything.

It seems to have started after I dismissed Piper on the Brotherhood of Steel ship to go do [censored] with Danse. After I finished the first mutant clear-out quest I went back to Red Rocket to dump trash and go do other side quests. I had no visible companion but Piper was nowhere to be found no matter where I checked. I did the brain explore quest with Nick and at the end says something like "I see that you're already traveling with someone what would you like me to do" I sent him home and manually went and asked him to join me getting the option to send the nowhere-to-be-found Piper somewhere. Sent her to Red Rocket. Fast traveled to Red Rocket, and nick didn't show up now... Rang my little bell and Piper came walking up. Asked her to travel, she says yes, then just starts walking off... Shut off the game.