Visio export to PDF has for the last few days mis-scaled the output - how to fix?

Hello.

I use Visio 2019 (desktop) to create large conversation trees. These are output to PDF using the inbuilt Visio export functionality. Since last week, the export functionality appears to be mis-scaling the output, resulting in the PDF cutting off a large part of the diagram as it is hitting the PDF 200 inch limit. To confirm, the Visio document is built to not exceed the 200in limit (it is 5m, just under 200in in width and much less in height).

This has always worked in the past. The problem is effecting both new and historic documents, including some very simply ones built to test the problem. 

Nothing has changed in relation to the print, page size or drawing scale settings. And as I say, it seems to effect all PDFs I export, irrespective of source. Naturally, I've explored these settings again once I found the problem, but nothing seems to change the behaviour. I've uninstalled and reinstalled Adobe, checked the document scaling (but this also happens on brand new document), etc.

What am I missing? Please help. Outputting to PDF is an important step in our QA process.... I had something similar many many years ago that was fixed by a hotfix....

Document in Visio

Export settings

Example PDF output (perfect square 200in by 200in partial document).

Properties of the PDF showing the 200x200in size.

Bob,