Problem with Planet hoster

hi all,

my website is hosted by Planet Hoster. they are very good and everything is fine but they faced issues with Piwik.
During the set-up 2 weeks ago, I have have had to contact them and they solved security issues.
It was fine during 2 weeks (and I really like Piwik) and Tuesday at 12h45 pm (Paris time), Piwik has stopped working. My last visitor was Tuesday at 12h43.

(see attached document)

My developer and I were not connected so we could not have done anything wrong.
We have implemented the new version automatically, manually, done all the tests we can. No success.

“System Check
Huzzah! There are no problems with your Piwik setup. Give yourself a pat on the back”

We have discussed during 2 days with Planet Hoster (which are good), they have modified a lot of parameters. They said that they have not implemented any updates or new version No succes neither. fyi, We use a VPS with Cpanel at Planet Hoster

If someone has any ideas to help us ( i really would continue to use Planet Hoster), it will be very appreciated

Thanks a lot