If you experience visual issues on the character fonts such as this example:

Then you need to disable font smoothing with a GPO.

In the Default Domain Policy, enable the 'Do not allow font smoothing' GPO: 

- run GPEDIT.MSC and go to

> Administrative Templates,

> Windows Components,

> Remote Desktop Services,

> Remote Desktop Session Host, 

> Remote Session Environment 

- open 'Do not allow font smoothing', change for Enabled .
- close GPEDIT.MSC.

Run CMD.EXE and type the 'GPUPDATE /FORCE' command to update the local strategies. 

You should first get 'Updating policy...' then 'User Policy update has completed successfully.'

Reminder : 

This is only available with Windows Server 2008, 2012, 2016 and 2019.