Help, this is driving me mad.

I have added a column to a MySQL table – varchar(1). I then added this column to an old datawindow that has been running for years. I changed the type to CheckBox, value on Y, value off N. Checked the rows update properties and added the column and checked the tab order. Also checked that it wasn’t protected. Done this many times in the past. Now, the problem is that I can’t change the value at run time. No problem in preview mode in the painter, that works fine. I can click on it and the focus changes, but nothing happens; the value doesn’t change (no tick). I have changed another existing column to a checkbox as a test, but with the same result, so it is not the column that is the problem. Clicking on the column does fire the clicked event and all looks normal except for the fact that the value doesn’t change. Apparently, something changes though as after clicking on it the row status changes to DataModified! If I change the column to type edit, I can change the value and save it fine, just not as a CheckBox. Sorry if this is a bit incoherent as I have been at this for hours and am getting really tired.

I must be forgetting something, but what? As always, any help would be appreciated. 

Gerry.

Powerbuilder 2017 R3 Classic