Website or App not loading even with all settings turned off. Nothing blocked in logs

Hi all,

like title says i cannot load website https://www.4ka.sk/ or their android app "Moja 4KA" with Next DNS turned on.

What i tried:

-checking my logs if it is blocked (i understand how logs work, in the beginning where i started using nextdns i fixed all broken websites by allowing necessary addresses)

-i put in allowlist every address related to 4ka.sk

-Checking if my ip is linked correctly

-turning all settings off (by "all" i mean really nothing was enabled in the settings)

-flushing dns on windows and restarting

-restarting android phone, turning wifi off and on, airplane mode, restart, app reinstall, wipe of app data

-I have next dns on router and also on mobile as DoH - the only way i can make this website work is to set dns on auto in my phone and using cellular data (that means i completely get rid of NextDNS)

This is the only web/app i cannot fix.

Any ideas? Is this NextDNS bug or the website is too sensitive to custom DNSs?