Global variable not changing on return from linked control app

From a form app, I’m linking to a control app.

[var] is set to zero from the menu app (onExecute). Inside the form I do not set it. I log the value in the db in onLoad and it shows as zero.

Control app has 2 buttons - Cancel and OK. Either button returns to the form app but clicking ok sets the global variable [var] = 1 in onValidateSuccess. Here too I log the value in the db and it shows 1.

The control app exits on clicking OK, automatically returning to the form app (without passing thru the menu app of course) but from the onLoad, the value logged shows zero instead of 1 just set.

In both forms I checked “session” only as scope and “in” as type.

I expect it to reference the same [var] global but it seems to have one copy for each app.

How do I get the desired behaviour?