My Bridge Has Been Collapsed again

As you can see here https://metrics.torproject.org/rs.html#details/CA39A0DD187313930099F0BD470E5EA676EB85C0 my bridge has been collapsed again. And I do not have the faintest idea why it has happened. What steps would you suggest in order to identify what has been caused that? And how to correct it.

This thread may help: