Hi there,
You seem to be running the following Tor bridge, which is great:
906D712825B2CA7FFDA9FA546BC6C3CA44030F14
But that Tor version (0.2.9.16) is obsolete, and because of old bugs, we will soon cut bridges running those versions out of the network. Please consider upgrading!
You can find Tor packages and instructions for your distro / OS here: https://community.torproject.org/relay/setup/bridge/
Ideally you will switch to keeping up with our stable releases, but if you need a stable that is especially stable, the Tor 0.3.5 branch will be maintained until Feb 2022: https://trac.torproject.org/projects/tor/wiki/org/teams/NetworkTeam/CoreTorReleases#Current and you can see the lifetimes of other Tor versions on that table too.
Let us know if we can do anything to make the process easier.
And lastly, I am copying the new network health mailing list (which has public archives), to help us stay synced: https://trac.torproject.org/projects/tor/wiki/org/teams/NetworkHealthTeam
Thanks, Philipp