I read this thread https://xenforo.com/community/threads/link-proxies-significantly-affects-skimlinks.70857
and I think I understand that it may be due to the new security check that is made on external links and prevents their script to be activated (only on simple click ??).
I tried to activate the links proxy (solution which was apparently efficient for Skimlinks) but the problem is still there
Is there an other solution ?
Many thanks for your help !