I couldn't find anything on their website for delisting, but it might be something your ISP will have to do if PerimeterX has a delisting procedure.
The other possibility is your ISP has let the VPS traffic go over the broadband ASN (either accidentally during a failover event or on purpose to help with load) and if that's the case it might just have an IP reputation too poor to be useable.
The other possibility is your ISP has let the VPS traffic go over the broadband ASN (either accidentally during a failover event or on purpose to help with load) and if that's the case it might just have an IP reputation too poor to be useable.
Anyway you can use a VPN?