Blurry/Pixelated Text

The upscaling works great for the graphics on my 4K monitor but the text is still blurry and pixelated. Any way to make text sharp too?

If you're rendering at 2160p on a 2160p screen there's no upscaling involved whatsoever. You're simply rendering at a higher resolution.
That being said, you didn't provide any screenshot examples to illustrate the issue, neither a log file.