Playing with friends breaks game

I started the game solo and played for a while before joining my friend’s game and then continued to play with him for over 10 hours but now when I return to my game solo not only has it not saved my progression but my whole campaign progression is glitched and I can’t land on Eden 6 this has now happened twice and I am forced to make a new character and play through the game entirely solo, please get this fixed as it is completely game destroying!