External Monitor Blurry text and Sluggy Mouse on MBP 2020 I have bought the MBP PRO 2020 13&quot; after lot of struggle convincing my family for lot of money. Thinking it would help me ease my work and help me with my work.
However,The problem is I feel like I have made a blunder on taking the decision. I have Dell P2719H 27&quot; Monitor and Logitech M331 Mouse.
I have used HDMI Cable to connect to my External monitor and tried costly HDMI cables as well (Belkin).
The mouse is very sluggy, I tried to move my pointer one place to another place. pointer became big and suddenly stops.
I'm feeling frustrated after an invested lot of my money in this thought that I will improve my productivity but I'm going behind fixing these issues for last ten days. Can anyone please help me.
Looks like I have time travalled to 2015 to have this kind of display text and sluggy mouse.
Any solution please help me to get rid of these both. Kind of losing my productivity on these things rather than focus on other work-related stuff.  I have reset my OS thought would help the issue and upgraded and downgraded. Now on Catalina.
System report :- 
Intel Iris Plus Graphics:

  Chipset Model:    Intel Iris Plus Graphics
  Type: GPU
  Bus:  Built-In
  VRAM (Dynamic, Max):  1536 MB
  Vendor:   Intel
  Revision ID:  0x0007
  Metal:    Supported, feature set macOS GPUFamily2 v1
  Displays:
Colour LCD:
  Display Type: Built-In Retina LCD
  Resolution:   2560x1600 Retina
  Framebuffer Depth:    30-Bit Colour (ARGB2101010)
  Mirror:   On
  Mirror Status:    Hardware Mirror
  Online:   Yes
  Automatically Adjust Brightness:  No
  Connection Type:  Internal
DELL P2719H:
  Resolution:   1920x1080 (1080p FHD - Full High Definition)
  UI Looks like:    1920 x 1080 @ 60 Hz
  Framebuffer Depth:    30-Bit Colour (ARGB2101010)
  Main Display: Yes
  Mirror:   On
  Mirror Status:    Master Mirror
  Online:   Yes
  Rotation: Supported
  Automatically Adjust Brightness:  No
  Connection Type:  Thunderbolt/DisplayPort
How is your HDMI cable connected to your USB-C on the MBP side?
I had similar issues and realised that certain combinations of HDMI or HP Display port cables in conjunction with cheap Ali-express converters to USB-C resulted in either a blurred external monitor or even sometimes in the MBP monitor being blurred and the external monitor being perfectly clear.
So if you have the chance, try using different cable combos, just to see if it makes a difference.