It turned out to be a problem caused by the caching plugin used by my hosting provuder!
Do you think thia is a BuddyPress related issue or bbPress?
Hi, I am sorry I do not have such deep knowledge of BuddyPress to answer. I am using the standard installation of both plugins with no modification and this odd behaviour of usernames is the “standard” one.
I have read around many people facing this issue and I was hoping that someone has found a solution.