Embed report viewport configured incorrectly with fixed width

This problem seems to have started recently... when I load the embed report URL in a mobile browser, it is sized completely incorrectly.

The report is configured with "Fit to Width".

Digging into the report HTML, I see that it includes:

<meta name="viewport" content="width=1200, initial-scale=1">

If I manually update the viewport content to use `width=device-width` as follows, then the report sizes as expected:

<meta name="viewport" content="width=device-width">

Can anyone help understand why this width is hard-coded to 1200? I've tried this with a couple of different reports and both have the same problem.

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