Just to add in case you have any use for this data: by now I cannot comment on posts or journals diretly at all, but most times by using the reading list.
Trying to filter the reading list always gets me a 403 error and isn't possible, and posting new entries works the first time I open my browser, but not the second time, but again after I close and open it again, always with a 403 error.
I'm currently not daring to delete my cookies again as I'm worrying to not being able to log in again.
I'm really glad there are so many options for commenting so it's mostly working!