Assuming you don't have direct access to the database to edit the portalalias table ('cause if you did, you could simply swap the portal alias id's)...,
Log in on something other than supporthome (maybe blade58) so that you can then delete blade58 as a portal alias - if it's a default, it means it is the topmost portal alias entry. And you can't delete a portal alias when that is the one you're logged in on.
That will bump the others up in the list, and since you don't mention any others, then hopefully supporthome jumps to the top?
Log in to the supporthome portal and create a portal alias for blade58 - it will be 2nd or more in the alias list, and no longer be a default.