I cannot change any more my settings (last name …) in myZwift.
You can make the changes on the app if needed.
When you are trying to update your settings, are there any blank fields?
Yes. I put a blank just before my last name.
But I just saw when removing those blanks that the problem is that required field ‘email address’ is erased each time I open myzwift window.And then the “SAVE” button is inactive.
I have to add my address in order to be able to modify the name.
As said by Paul, app (mobile & PC) work fine.