If you are having issues with staying connected to your ArcGIS Online account via the Survey123 connector within Microsoft Flow then I have a solution for you that does not require you to go into each Flow to reestablish your Flow.
I the past I have had to go back into each webhook that I had setup within Microsoft Flow every 4-6 weeks to reestablish the connection to the my Survey123 account. It would take a little while to go through and ensure that all my flows had been updated with the new connection.
Today, I decided to try something different, instead of going into each Flow, creating a new connection once that allows me to see the name of my survey, and then going into each Flow to use that new connection. Now you can simply do the following –
After completing this, then go check out your Flows and you will notice that "all of them" have been updated to their original status. This seems to be the easiest way to reestablish the connections for "all" of the flows that I have setup.