I've recently purchased some 4k blurays and am having a hard time with volume keys, I haven't been able to find any working solutions to my two movies, however the regular bluray discs that came with work fine which leads me to believe this is something to do solely with the UHD discs.
Here's the dump file, please let me know what else I need to do, or any advice.
Using LibreDrive mode (v06.3 id=866A98CB9C4E)
Using direct disc access mode
Loaded content hash table, will verify integrity of M2TS files.
Downloading latest HK to C:\.MakeMKV ...
Automatic HK downloading is disabled or failed.
Saved AACS dump file as C:\.MakeMKV/MKB20_v61_Batman_Begins_A24F.tgz
The volume key is unknown for this disc - video can't be decrypted
Failed to open disc
MakeMKV tries to download the necessary hashed keys when it needs to decrypt a 4K UHD (and AACS v82 regular blu-rays). That line in your log indicates that there was a failure when it tried to download keys. The server moves around from time to time and is located in Russia. Often people have some kind of 'geo blocking' turned on in their router or firewall that trips them up. Sometimes people's ISP is unhelpfully blocking the request.
I'm not sure what you mean by "xfi gateway". Does xfi mean Xfinity/Comcast? In the past, people with Xfinity have had to turn off 'advanced security' to be able to download hashed keys.