I am encountering this issue and I've seen a few discussions about it without a clear cause or answer.
So, I am currently running a few flows, one flow for each one of our Shared Mailboxes. They are all using the trigger [When a new email arrives in a shared mailbox (V2)].
The flows run just fine, as I do have access to the Shared Mailboxes, however I do not have admin rights, and the Mailboxes do not have login credentials enabled.
A couple of the Power Automate flows run flawlessly, they are always online and no hiccups whatsoever. No issues there.
But every once in a while, another set of flows give me a [Bad Gateway] error in which they just stop running altogether. This happens more often to one of the flows than the rest, the others are a bit less frequent, but it does happen and like I said, a couple of them never encounter this issue.
To fix it, and continue running them, I simply re-create the flows (Save As) and turn off the old flow, and turn on the flow copy, and it runs fine until it happens again.
All the flows are set up exactly the same way. I created a base flow, and just copied it for each Shared Mailbox and edited the initial trigger with the Mailbox addresses, nothing else is different between the flows.
Is anyone else facing this issue? It is not a crippling issue but having to constantly be checking the flows and missing some work due to the downtime is a bit frustrating.
I wonder what the underlying issue is and if the only fix is to get admin rights or login credentials for each mailbox but currently that is not a viable solution.