Try these:
1) disable any other third party vs extensions except Telerik extensions under Extensions-->Manage Extensions
2) reset all vs settings under Tools-->Import and Export Settings-->Reset all settings
3) clean all nuget caches or delete all files under C:\Users\xxx(current user)\.nuget\packages
4) close VS Instance, delete the nuget.config
file under C:\Users\xxx(current user)\AppData\Roaming\NuGet
and then reopen VS to regenerate it.
Then, add telerik
nuget source on the nuget package sources under Tools-->Nuget Package Manager-->Package Manager Settings.
add https://nuget.telerik.com/nuget
as telerik nuget source so that you can access telerik.reporting.services.webapi
.
like this:

Besides, if you still cannot face the crash issue under step 4, please try to repair vs or devenv.exe / resetuserdata
under Developer Command Prompt for VS2019
.
In addition, you can try to reinstall Progress Control Panel under telerik website with your own account.

Last, this is my result:
