I was having this issue. I’m using the beta version and it has significantly improved the performance. You can get the beta by following the below instructions:
Open the Steam client
Right-click Darktide in your Steam library
Select ‘Properties’
Select ‘Betas’
Enter the password cTYPtKTsfMDsLHAV
Select ‘Check Code’
Select the ‘None’ dropdown, and experimental - Experimental Builds should now be within the list
Select experimental - Experimental Builds
Close the pop-up window
A download should now start
Navigate to your Darktide AppData by:
Press the Windows key + R
Enter %appdata% within the search input and select ‘OK’
Navigate to AppData\Roaming\Fatshark\Darktide
Open the user_settings.config
At the VERY TOP of the user_settings.config, enter the line disable_dstorage = true