No Matt, that is not the case. This was not happening for just one plan. It was across the board. At the time I posted Friday, I had 35 jobs in overdue status stuck in various states (starting, checking for modified files, preparing, etc.)
Of those devices, the logs stated, "GetEndUser url is 'https://ws.mspbackups.com/webservices/EndUser2.asmx'"
"Error on calling webmethod, retries will be performed. Status: ServiceUnavailable"
Then the plans ended up failing because they timed out with "The request failed with HTTP status 503: Service Unavailable".
All of this information is in Ticket #203885

You are saying you want me to send you logs from potentially 85 affected devices when this happens again?

I guess I didn't receive the email stating there was scheduled maintenance on Friday 4/5/2019 starting around 8pm and continuing for several hours. Did I miss that one?

However, I did receive the email stating there was scheduled maintenance Monday 4/8/2019 between 1 am - 2 am.

Here is my main concern. We went live with our clients on April 1, 2019 after switching from BarracudaMSP. This is not a good beginning so far.

This is happening again. Same behavior as 3/31/2019. Client consoles will not open. Backups are Overdue and stuck "Searching for modified files" or "Starting".

We use BlackBlaze B2, so I don't believe it was a storage provider issue. At a quick glance, our storage amounts appear to be correct. 5 hours ago, I received this from Support: "We're aware of these issues. Services should be up an running very soon."

It started with Clients/Consoles not opening. I thought it was environmental. Then after checking a few hours later, 54 Overdue backups! Error: "The request failed with HTTP status 503: Service Unavailable."