Why is number 1 displaying as 1§64

In Calc 5.4.3.2 (iMac, High Sierra) if I enter number 1 it displays as 1§64 but if I enter 1.0 it displays correctly.

And what is the cell number format?

General
0 decimal places
1 leading zeroes
Thanks gabix

And your locale?

I’m located in the UK

I mean the locale as defined in the LibreOffice settings. Also, could you share a sample file? I can’t reproduce such a problem with the locale settings for Belarus and the default (general) number format for cells. And even if I change the locale to English (UK), I still can’t reproduce.