Yes, I have had the same issues and the IP provider (a local phone coop) does not elaborate on why it happens. I would connect but only get a blank page.
It is done with a script, when I saw it happened I noted the script working. Searched that on duckduckgo.com and here is a list I found which contained the script:
DNSCrypt-Proxy-BlockRules/Blocked-Names.txt
https://github.com/ACEx86/DNSCrypt-Proxy-BlockRules/blob/main/Blocked-Names.txt
The local access provider said the problem was in my browser. Well, when I tried Internet Explorer it worked, sort of.
But it would not work with Pale Moon that I typically use.
Yep, and it is not the browser. I have tested this extensively with different browsers. Some browsers are easier for them to block than others. But it all starts with them attempting to block it. Here is another one... I have also noticed that there can be a difference between one IP server and another when they shove random dynamic address access on you.
The blocking is worse on some of their servers than others, I can disconnect and reconnect hooking through a new different IP server and address and it is fine. I now have the problem addresses logged so that I can tell right off hand I will probably have trouble using that one. So I disconnect and reconnect until I get through a good one.
It is almost like each IP server address administrator has personal discretion on what they want to block or throttle down.