It’s just an NTP pool. The device is trying to update it’s time. Likely it made many other requests to other servers when this one didn’t work.
Maintaining up to date lists of anything is a game of whack a mole, so you’re always going to get weird results.
If you’re actually unsure, pcap the traffic on your pfsense box and see for yourself. NTP is an unencrypted protocol, so tshark or Wireshark will have no problem telling you all about it.
That said, I’d still agree with the other poster about local integration with home assistant and just block that sucker from the Internet.
My brother in Christ, scope your sessions… Firefox has containers, chrome has profiles, or hell, just use two different browsers.