Quest Progression In Solo Play Not The Same As Co-op

So far I’ve completed the Normal play through, started TVHM, and made it to Promethia. Playing with my friends the entire time, we never completed any quests without everyone being there and my friend was the host 100% of the time. I tried playing in solo play and it started me from the beginning. So far I’m on the quest to kill Mouthpiece and have not received a prompt to skip. Did I do something wrong or is this just a bug?