[tor-relays] Bridges and Hs_vanguards

[dmz21]

Dear readers,

During the last week the bytes/second of my bridge dropped to 20% of its common usage over the past months, while the average number of connected clients stayed the same (according to metrics.torproject.org).
I'm also seeing a dozen circuit connections with purpose Hs_vanguards in nyx recently, which are not familiar to me.

Under-utilization of my bridge is not a problem to me, but maybe someone can tell me whether the two are related?
Maybe it's an issue at my end or my hoster or maybe a generic issue of the tor network currently? Or maybe it's all normal?

Thanks and best regards