Microsoft Word Freezing - em-space and tab

Microsoft Word (up to date licensed 365 – 16.50) has frozen for me under MacOS (up to date Big Sur – 11.4) on an Apple Silicon Mac Mini M1.

The document I was editing had been created under Windows and saved to OneDrive.

Opened on MacOS and, initially, all was well. But as soon as I tried to add a tab character it froze and I got a beachball. Had to force quit.

Repeated this several times, edited variously to try to identify the issue, and came to the following conclusion:

If you try to add a tab next to an em-space, Word freezes. This does not happen under Windows.

I had used multiple em-spaces (for reasons outside this note, it is a technique that works in another circumstance where ordinary spaces displayed in html collapse).

I edited the document and replaced all em-spaces by ordinary spaces and the freezing was resolved.

I have also had no issue with em-spaces and tabs added to a document under MacOS.

However, we should be able to use em-spaces – whether inserted under Windows or MacOS – on either platform.

Am posting this not in the hope of a solution for me – I can live with it – but to document the issue and point in the direction of a possible workaround or solution. And to hope that someone in Microsoft or Apple notices. There are other reports around – some mentioning em-dashes.