@PrintableCharacter did advice you to allow that specific site, or to try a different Host list.
Did you do that already?
Please check the menu Adblocking / Host log after you accessed that domain. Does the domain show white as ‘accessed’ or orange ‘as blocked’?
Okay. Good.
Now, in the Host log: tap ‘Clear Host log’. Leave the Host log menu. Then try to access the page. Then check the Host log again (spit-screen mode can be very useful there). If you see a blocked entry, that could be related to this site: tap on the entry. Tap ‘allow’. Then try to open the website again.
If you want help figuring out which entry needs to be allowed just send a screenshot of the Host log:)
@c_C while discussing with this, a thought just crossed my mind. Could it be possible that vpn can be detected by webserver and block itself from sending the contents in response?
Okay, do you use a custom DNS? If so please disable it. If not, please select one, my recommendation for this test: Quad9.
In the DNS menu, is DNS Fallback enabled? If so please disable it.
Are you using Chrome or something Chrome-derived? And did you follow the steps relevant to make Blokada work with Chrome?
Okay, I checked Cloudflare doesn’t block the domain for me either…