Tried the main mirror, and nothing new to update/upgrade from command line, and the mintupdate GUI too...
So, if I've understood informations from the mintupdate GUI, my system is currently using UP4, and inform me UP5 is online ?
No problem if the computer is updated, it's ok for me
May be a little bug in the mintupdate GUI (if I've correctly understood
Thx for your answer, mister.