Cannot unhide columns in Mac Numbers 13.2

Columns to the left hand side: cannot unhide, making files unusable.

I can hide and reveal other columns but in one file A and B are forever hidden, and C is only partly visible.

In a second file columns A through E are hidden and there are no menu options to reveal or unhide all.

I Excel, you just highlight the column range that is hidden. That isn't possible if columns are at the left hand side of the Numbers sheets.

I haven't merged cells.

This undermines a huge amount of work setting up spreadsheets. It affects multiple sheets in multiple files...

Any suggestions of settings that might interfere with the Hiding/Unhiding?

Thanks for any assistance