I’m experiencing this issue on several BOINC projects.
Whenever I try to change my name, I get the following error message: That name is in use - go back and try another.
I’ve already posted about this problem in the forums of those projects, but I haven’t received any replies :-(

I’ve already posted about this problem in the forums of those projects, but I haven’t received any replies :-(

I saw the post on CPDN fora. I never listed my now discontinued website and with no knowledge of the server code, don't have any ideas which is why I didn't reply. The person I would have raised this with at the project has left after many years. Glenn does follow the forums but has a lot on his plate and is a volunteer to boot. Some other projects I have noticed are not at all good at responding, but given you are experiencing the same issue at several projects, raising it here is probably a good idea.

Little correction: "Whenever I try to change my website URL". Not name.

What is the problem? You can't change your name? You can't change your URL?
What error message do you get?

Can't change website URL. I see this error: That name is in use - go back and try another.

You don't change the username at the same time either? As that error message only happens when the username is changed, and it's found that that username is already in use.

I don't. Just the URL. It's quite weird.

Which project(s) do you have the problem with?

These 3 projects:

https://boinc.multi-pool.info/latinsquares/forum_thread.php?id=240

https://escatter11.fullerton.edu/nfs/forum_thread.php?id=924

https://main.cpdn.org/forum_thread.php?id=9405

I just tried at CPDN to remove the URL I have from my account, and add it again, both times saving changes. I don't get any error message.

So.
Change Other Account Info.
Remove the URL you have.
Save changes/Update info.
Change Other Account Info.
Add the URL you have.
Save changes/Update info.

If that doesn't work, what is the URL you're trying to use?

It doesn't work for me. That's super weird.

I can't edit my profiles basically. It's not just the URL. Everything I try to change is not accepted because of: That name is in use - go back and try another.

The URL is https://consulente-finanziario.org anyway and I changed it without problems in the other projects.

In case of CPDN you are trying to change it on https://main.cpdn.org/home.php? (Certainly check it's https.)

It's possible your URL is seen as spam.

Yes. The HTTPS one. But I don't think it's about the URL, since it happens also if I try to change my country.

Which browser do you use?
Tried to remove cookies for the affected websites?

That's about the only thing I can still think of before handing it over to someone else.

Sure I did. I also tried with different browsers such as Edge, Firefox and Chrome.

Then best make it a ticket over at the Github page of BOINC, perhaps that they know what could be doing this.
https://github.com/BOINC/boinc/issues