From the [Synapse 1.43.0 release highlights](https://matrix.org/blog/2021/09/21/synapse-1-43-0-released):
> Asks clients to prefer [room version 9](https://github.com/matrix-org/matrix-doc/pull/3375) when creating restricted rooms ([#10772](https://github.com/matrix-org/synapse/issues/10772)), via the API defined in [MSC3244: room version capabilities](https://github.com/matrix-org/matrix-doc/pull/3244).

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1322

I am not using this bridge and haven't tested this but multiple people have said 1.5.0 isn't working and 1.8.0 works for them so it seems to make sense to update.

https://github.com/matrix-org/matrix-appservice-slack/issues/618#issuecomment-929849093

for matrix_nginx_proxy_proxy_synapse_metrics_basic_auth_key
resolves #1308

when matrix_nginx_proxy_proxy_synapse_metrics is enabled