reMarkable services won't work with this blocklist

[panosru]

Hi, I'm using AdGuard DNS and when I have Perflyst and Dandelion Sprout's Smart-TV Blocklist enabled reMarkable service isn't working.

From monitoring the traffic I found the following domains that are used by the service:

• ping.remarkable.com
• webapp-prod.cloud.remarkable.engineering
• updates.cloud.remarkable.engineering
• internal.cloud.remarkable.com
• notifications-prod.cloud.remarkable.engineering

There might be others as well, but those are the ones I managed to capture. I'm not sure though as to why they are blocked, I don't see any rule in the list that directly blocks remarkable, or .engineering TLD.

I disabled all my rules and left only Sprout's Smart-TV Blocklist just to make sure that it is indeed that blocklist to blame, and still, reMarkable services wouldn't work unless I disable this blocklist. When I enable all my rules and disable this blocklist, then it works again.

Thanks!

[DandelionSprout]

Sounds like it could be a problem with AdGuard's implementation of CNAME lookup, and as such it's not 100% clearcut which entry that'd have to be whitelisted.