first time column autosize in TStringGrid doesn't work

[inferno]

Hi all,
I have a small issue with autosizing columns widths in TStringGrid by doubleclick in header row (goDblClickAutoSize:=true). When trying to autosize any column first time after start the application it doesn't work - after first click the cursor changes from crHSplit to crArrow and column is not autosized. All next doubleclicks works properly - crHSplit coursor is kept until second click and column is autosized.
Any idea why this happens?

Platform: macOS 10.14.6+Cocoa

Best regards,
Inferno