Hi,
1. Check if you are using correct drivers for your Laptop.
2. For older drivers, head to Dell's website and under drivers and software, select your product and download the appropriate drivers under the "Video" category.
As per the information you provided, https://www.dell.com/support/home/en-us/product-support/product/inspiron-15r-5521/drivers
3. Older drivers might not work as they were originally meant for Windows 7 or so.
So, try installing newer drivers for Windows 10. Download them from AMD's website (https://www.amd.com/en/support ) by selecting appropriate make and model of your GPU (Graphics card).
4. If you want to run those old OEM drivers (version 8.x), try running them as compatibility mode by: extract setup > run Setup.exe in compatibility for [Windows 7] > install.
I would recommend you to better go with somewhat newer drivers (NOT LATEST [Adrenalin]) as latest drivers do have some issues with GPU selection on some systems.
See if "https://www.techspot.com/drivers/manufacturer/amd/ " has some drivers you need because AMD has removed old drivers from website. [NOTE: Use the site at your own risk. I DO NOT say that the source is only available or is virus-free]
I would recommend you to go with driver version lower than AMD Adrenalin 19.12.1, because that's the point where we have a choice to choose GPU independently for a process/application. After that, all latest drivers DO NOT have that option entirely.
Hope that helps.