Can you present some prints screens, in order to try to help you?

I have the same issue: as soon as two or more users edit a swim lane title - it stops working.

example: in a fresh preset Kanban board (screenshot below) : 
If someone renames a swim lanes title (“Team B”) its ok - but as soon as another also edits the title, it kicks the first user out. If many users do so, it’s kind of impossible to edit the title.

Issue is the same if you have different kanban boards on the same miro page. The users block each other from changing the title.