@trinity-1686a there may be much easier explanation: it happens because of bug, which no one wants to deal with:
https://gitlab.torproject.org/tpo/anti-censorship/team/-/issues/112
https://forum.torproject.org/t/my-bridge-seems-to-be-offline/6117/1
Same “offline for 2 hours” happens also for Conjure bridge:
https://metrics.torproject.org/rs.html#details/A84C946BF4E14E63A3C92E140532A4594F2C24CD
It have single instance, right?