Exporting to PDF changes size of displayed score

I finished working on a small 3-line score for a trad tune in MuseScore4.
(Lovely that I could do that, and hear it in the process. Thanks)

I exported to PDF and saved the file.

When I reopened the file later, the score was huge,
Only the top-left corner was showing in the score window.

The workaround was to export as a MusicXML file.
When I closed the file, it asked me if I wanted to "save changes".
(I hadn't actually changed anything, but I did, in hopes that was the bug.

When I reopened the file, it was now properly sized.

So:
1. Exports are seen as changes, but they shouldn't be.
2. I can't see the cursor in this community window, which makes the report more difficult.
3. When I used the contact window to report it, the option to send myself a copy didn't work.
4. The auto-reply I got back sent me links to the handbook and the forums (very nice), but
didn't tell me if anyone was actually going to see my report.
5. I looked for existing reports before filing this one, but the 2 searches I did both returned
10 pages of results. My apologies if my failure to inspect 10 pages of possibilities results
in a duplicate report!