Hi ,
thank you for your investigations,
yes there was an great amount of hacking attempts on our servers this year, all failed, but a firewall was added by provider in July,
so Wget and some spam would be blocked.
i run a ssl-labs checks and certifcates are ok, probably it detected the wget during ssl negociation.
we normally whitelisted bots including google (using the official json)
but it's a possibility that it could be blocked/redirected to human check if using unidentified source ip range or user agent to do some checks from outside of Chrome.
Google search console does not show any alerts or connectivity issue.
we desactivated the firewall on some of the domains to check if it's coming from that.
thanks again for your inputs
regards,
André