Just upgraded WEB code to 2.7.2.0 and the result is the same for me.
However switching the scale while the application is executing in the browser does not show the problem. If you run the application with 100% and then change the scale to 150% (other than 100%) and refresh the browser so that application restarts, the problem will show if drop down is activated. You can see this in the screen shot.
I tested this on two machines and I cannot reproduce this.
Also, it is not clear whether you refer here to browser scaling or machine display scaling.
I tested it with
100% DPI : 100% browser scale
100% DPI : 150% browser scale
150% DPI : 100% browser scale
150% DPI : 150% browser scale
each time with restarting the web app and in none of these scenarios, I could reproduce a problem.
It seems the behaviour varies under different conditions. Here is one that consistently behaves the same:
set windows screen resolution as 1900 x 1200 and scaling at 100%.
Create a web project at this resolution and scaling.
drop a WebDropDownComponent
drop a webpanel and a button in it
set dropdowncontrol control property to webpanel and compile the project.
To test the effect find the exe in the win32 folder and run. After each run close the web browser. At windows scale 100%. It looks good. It looks good on every windows scale except 175%. The panel is put on top of the dropdown at this scaling .