You have hardware monitoring enabled in the Clarrett 8. You need to read the appropriate Focusrite manual. What one are you using now?
Work out if your interface uses the old MixControl or the newer Focusrite Control. For a USB Pre I think it may be Mix Control. I would hope that info would be clear with whatever Focusrite supplied with your interface.
MixControl
https://support.focusrite.com/hc/en-...Creating-Mixes
User Control
https://d2zjg0qo565n2.cloudfront.net...user-guide.pdf
Nothing related to Pro Tools here.