Numbers spreadsheet not showing 5 out of 11 columns

I have a spreadsheet with 10 columns, the first ( A ) shows then 5 (B, C, D, E, F, ) are hidden and the remainder ( G, H, I, J, K, ) are normal. I can slide the columns on the right to reveal almost all of F but it springs behind A when released. I think this occurred after I updated Numbers to version 11.2 (7032.0.145).

I could revert to the old version on Time Machine but would rather resolve the issue. Any ideas?