an app using your code(?) on the microsoft store
https://apps.microsoft.com/detail/9MZ625MT9GJW?hl=en-us&gl=US
all the settings are the exact same the ui is just different and it sells for one dollar
by the screens itself it looks like everything is done according to license, but if you have access to the software can you verify if the source code of the published app is available with proper build instructions?
it's not open source, they're selling for money (i dont have access to it btw)
i just went to search for roundedtb and that popped up
on the screens you provided there is a link to source code but it's not clear if it links here or to the derived code
being open source, including GNU GPL 2.0, doesn't stop you from charging for convenience, but it requires all derived work to be compliant too
it's a fork https://github.com/chanallenk/ClassicTaskbar this is the link that was in the ms store page
The owner of this repository will need to report it then as a copyright violation I think.