Tools to diagnose this issue do are non-existing. → Forum.onion unable to connect - #25 by Patrick
Server configuration and output of onionprobe is almost identical, except for the places where it necessarily needs to be different. (descriptor, domain name)
Kicksecure:
onionprobe -e w5j6stm77zs6652pgsij4awcjeel3eco7kvipheu6mtr623eyyehj4yd.onion
Whonix:
onionprobe -e dds6qkxpwdeubwucdiaord2xgbbeyds25rbsgr73tbfpqpt4a6vjwsyd.onion
What makes a relevant difference is the state of the Tor user’s local Tor daemon.
I have reproduced multiple times that an unreachable onion becomes reachable after restarting Tor. Similar reports can be found online:
When a Tor restart is required and fixes anything, that can (almost) always be considered a bug in Tor as Tor should be able to recover from this without restart.
I would say “try onionprobe”.
sudo apt update
sudo apt install onionprobe
But the problem is, it’s not compatible with Whonix because onionprobe - I assume by design to avoid above issue - starts a temporary (throwaway) Tor daemon - before probing an onion.
Hence, onionprobe isn’t suitable to be run from within Whonix and only from Debian, Kicksecure or similar. [1]
If running onionprobe from Debian, Kicksecure or similar is fine for anyone, try it.
[1] onionprobe supports --no-launch_tor but requires Tor control protocol access, writing an onion-grater profile might be possible, but it would be a lot work for a non-ideal result using onionprobe different than it’s designed to run by default.