TStringGrid is automatically widening its first four columns

[Alin 1]

Since Delphi 12.2 or so, many of my FMX TStringGrids in an application act erratically.

Tonight I managed to isolate and reproduce such a bug, on Delphi 12.3 and Delphi 13 (didn't try earlier versions), and on Windows 11 Pro (licensed, updated, no mods).

It's a very short program, with almost no code, so I strongly believe the bug is in Delphi and not my fault.

It contains three TStringGrids and if you scroll (with scroll bar or mouse wheel) to the bottom of the TVertScrollBox which contains them, one of the TStringGrids always starts increasing the widhts of its first four columns by +3, indefinitely, and quite fast.

Also, in certain conditions, quickly rolling the mouse wheel to scroll downwards and rapidly moving over one of those StringGrids will generate the same effect (columns start to increase in width and if you don't click anywhere they will increase indefinitely, sometimes in two or three TSGs at the same time).

And if you hide the first TSG, then the third one does not increase the column withds if you scroll down with the scroll bar but it does if you scroll down with the mouse wheel (if you did not scroll down with the bar first). Truly strange behavior and I can reproduce it 100% of the time.

 

Has .anyone. encountered this kind of weird problem (TSG increasing its column withds)?

 

The program is small but the form has a specific setup (layouts and a vertscrollbox) so I don't know how to post it. Perhaps I can as a  zip file, if anybody wants to have some fun with such a bug?

If that simple layout is not in that simple setup (three non-visual elements aligned to Client), I could not replicate the problem (to always take place). And I need that specific layout, as this example I built is actually a completely stripped-down version of my real app.