TOPIC:

Did a lot of experimenting on Linux Mint 22.3 (GTK2) with windows that have a gradient background (plGradient) and Checkbox and/or DBCheckbox components and it is still very unpredictable.
On my Linux test project I sent you earlier everything works as expected but on one of my projects everything works fine on my Windows 11 machine but I keep having the checkboxes hidden by the background gradient even after moving the gradient to the back.
See the attached screenshot.
I hope you can give me any suggestions, for this is really getting me crazy. 
 

The continuing story of .......... 
I did a comparison of the generated frm file in Windows with the same frm file in Linux of the offending unit in my project and I see some strange things in these files.
Mostly the TDbCheckboxes that I do see in the Windows version don't appear to be in the Linux frm file or are completely misplaced in the Linux frm file.
As a test I copied the missing parts from the Windows frm file to the Linux frm file and recompiled my project in Linux, but still the Checkboxes do not show in the particular window tabsheet. 
I have no idea what goes wrong with this particular unit in Linux but something is obviously not right.
Can you guys please give me some advise on this?

My suggestion,
Copy *.frm and *.pas from Win to Lin.

"Form" files *.frm and *.pas must be the same on any OS
 

That is how the project came to Linux, by copying all sources from windows to Linux and I had no problems with it but after some time (and CT 9.00) the checkboxes dissappeared behind the gradient.All other components like labels, edits and comboboxes do show in front of the gradient.So I am still at a loss.