I got these same messages this afternoon East Coast US - around 4:00-5:00. By 6:30 the issue went away. Not sure why it happened or why it stopped. It only affected mobile apps (you could access everything without problem through the PC) - we connect to sharepoint and Microsoft 365 users - nothing else.
I was having this issue temporarily, but it seems to have been solved by checking and updating my connections.
From your powerapps editing page, go to File > Connections.
Make sure all of your connections are at the status of "Connected". In my case, on of them had either expired or needed to be re-authenticated. I did this and the error now no longer shows.
Hope this helps,
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