I have one site on a server in France, which is a vanilla installation of CP. I visited it to try something and saw it was saying there was an update for v1.1.1
I clicked on update, but it didn’t happen. I then noticed the disk usage was around 150MB. There were multiple instances of past failed attempts to upgrade in .cagefs>tmp
In wp-content>upgrade the files in the temporary folder did not contain all that they should. I increased the script execution time in php.ini to 300 seconds, but the update stalled well before that. The screen also remained blank during that time, with no progress messages.
There was no maintenance file left over in the root directory, and it didn’t seem to be going into maintenance mode at all.
So I deleted all the temporary files to bring the disk usage back to around 35MB and uploaded a ‘no- content’ version via FTP. The site was then happy and the update notice went away.
Apart from the French location, the only difference between that server and all my others is it doesn’t run LiteSpeed, only Apache.
Just thought I’d mention it, in case it highlights a potential problem. There were no cPanel errors or error log file entries. It just seemed incapable of updating itself. It is running PHP 7.2