I have the same issue, even after factory reset of firefox and syncing with a brand new account, adding the containers extension back in results in it trying to open every container in the same container.
This was one of the reasons I enoyed using Firefox so much in the first place (containers are a fantastic way to make sure you don’t accidentally log into the wrong customers portal) now its completely unusable for me.
All I need to do is turn off the always open option (please)
NB as suggested above - none of the suggested (easy) fixes for this issue work - I have had to turn off containers altogether.
Correct. I have to do that multiple times per day. I’m testing the behavior with container sync disabled but ideally I would find a solution that keeps sync enabled.
I tried to reproduce it without success. You can try the instructions on https://github.com/mozilla/multi-account-containers/issues/1661#issuecomment-591506621 to completely clear the sync data for Multi-Account Containers. I don’t know if you need to turn off Sync on all devices before clearing or if it’s enough to do it on only one devices. So you might have to experiment a little with that.
Sorry I don’t have a better solution to propose :(.