uceprotect blacklists the full subnetwork of my VPN: how to have OVH fix things?

my SMTP server on the subnet 51.77.0.0/16 is blacklisted by http://www.uceprotect.net

I have had an SMTP server at OVH for at least 15 years, and went through all the pain of keeping it with a high reputation: VPF, DMARC, DKIM, removing myself from the occasional blacklists.

Now, this blacklist maintainer is flagging the whole subnetwork on which my server runs: http://www.uceprotect.net/en/rblcheck.php?ipr=51.77.140.222 possibly because spammers use OVH VPNs at nearby IP addresses.

According to the documentation, only OVH can act to redress the situation and have UCEPROTECT unlist its subnetwork.

Anyone encountered similar problems? Any fix? Apparently, we can *pay* to be whitelisted, which is a complete scam, so perhaps this UCEPROTECT is actually not so honest in fact.