Yesterday (2nd September) I was able to import/export PowerApps. Today (3rd September) both the Export and Import operation only get as far as "Creating your package" or "Importing your package" and then freeze.
I've tried with two different Apps on two different tenants with the same result, so looks like this could potentially be widespread...
Thanks all for raising this - can someone please send me a private message with a support incident you've raised? I'd like to check in on it's progress.
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