This issues it related to #7023 (closed)

I saw at privacy handbook that Gajim is not resolving DNS over TOR. Or check at Tor wiki. To check, I enabled the Tor Proxy in my account settings, started my client and looked for DNS requests with Wireshark. I could verify their claims.

I think, this is not the expected behavior. If you use Tor, you don't want anyone to know, which hosts you connect to. At least the domain names related to a "torified" account should be resolved over Tor. Another strategy would be to proxy everything over Tor as soon as one account enabled Tor.