I believe he only mentioned receiving the new card with the new TT number. From here you have to activate it and link it to your passport.
I would assume that you can renew and get a new TT number but it won't work for TSA precheck unless activated and linked...and...changing your TT number on airlines saved info would be next.

I am interested in the results 'cuz I will need to do the same soon...

I would first try, as suggested, a different browser before going any further though