Hosting providers should be good citizens of the network and immediately terminate spammer accounts. This used to be standard practice until about 2015. When suddenly management decided it’s more profitable host spammers than not.
I think this is a great policy decision by uceprotect.
At one time quite recently, Cloudflare was on Spamhaus's "Don't Route Or Peer" list. Imagine where the world would be if anyone gave a shit about that list.
But if an entire ISP is blocking you based on UCEPROTECT, which is designed for email spam filters - are you sure? An ISP that blocked all of DO would get so many complaints and be open to so much legal liability. Usually these are only used for email filtering.
As I explained, Orange's security filter seems to automatically block requests at the DNS level if your website's domain resolves to an IP listed on UCEPROTECT Level 3. In this case, that appears to be the entire DigitalOcean ASN.