I have upgraded my Free cluster to Flex and now without changing anything it does not connect. My whole app and website are down for hours!
I have access from everywhere enabled, and the connection string is the same as before.
mongodb+srv://:@cluster0.*****.mongodb.net/
mongodb+srv://:@cluster0.*****.mongodb.net/?retryWrites=true&w=majority&appName=Cluster0
Neither compass or the app are able to connect anymore.