Problems with using HP 27fw external display on a MacBook Pro when running macOS
If by HP27fw you mean this display, then you may have gotten a fairly low end 27 inch display.

For example on my work PC (Optiplex 7060, Win-10) I have three Dell 24-inch displays that are set to their native resolution of 2560 x 1440. So, you ask, what does that have to do with my display on my Mac? Glad you asked.

The specs of that monitor say


  Recommended Resolution 1920 x 1080 @ 60 Hz (FHD)


And it makes no mention of any other resolutions that are supported.

So what you have here is a monitor that is 3-inches larger than one of my displays and yet it has a lower resolution.

While the display resolution of a monitor can have a lot of different available resolutions a good quality display that supports a resolution that will look good on your Mac at 27-inches is probably closer to 2560 x 1440. And if you want a really high end display at the 27-inch size look at a 5K display at 5120 x 2880.

I would say that you got a display that will work with your Mac, however it will not work well with your Mac and you need to get one with a higher native resolution to properly display the video output the Mac is capable of.