It is now known that UCEPROTECT RBL is a blacklist classified as a scam as it lists clean IP addresses and then asks you to pay for the removal of your IP.
Since this is a fake list, UCEPROTECT RBL or blacklist reports should be ignored.
You can find a detailed analysis of what UCEPROTECT RBL does at this URL : https://blog.sucuri.net/2021/02/uceprotect-when-rbls-go-bad.html
