Activation of Photoshop 2018 not working

Hello,

I have a subscription for Photoshop; I am using the 2018 version on osx High Sierra (max version for this OS). I was happily working with this configuration when suddently a popup window appreared mentionning that I have no subscription. I called the local support 3 times (very nice persons); we spent several hours trying to debug but no succes. I cleaned the cache, deleted everything, re-installed a 2018 version, they verified that everything was normal on their (Adobe) side. Now when I open Photoshop I have a window mentionning that it is a trial version. Everything looks normal when I open Creative Cloud, I have access to my account informations, my applications etc.   I tried on another Mac: same thing, my subscription seems not recognized by adobe. 

Would anyone have a bright idea about the origin of this problem ?

Thank you !