Insertfield statement misbehaves with more than 20 similarly-named fields

I have a database whose fields include Alpha1, Alpha2, etc., through to Alpha22. This code:

field Alpha1
insertfield "Alpha0"

inserts the new field but it displays in the data sheet as following field Alpha20. Saving, closing and re-opening displays the new field in its correct location, preceding the Alpha1 field. This happens for any number of Alpha fields greater than 20.

If I reduce the initial number of Alpha fields to 20, the new field displays in its correct location.

I have replicated this behaviour on two Macs an in each of the two most recent versions of Panorama X.

And, even worse, if I follow those statements with:

field Alpha0

I get the “requested field does not exist in the current database” error message.

I think that there may be some conflict with line item field properties.

That sounds logical.