Fuel filters are perhaps better placed between tank and fuel pump because it doesn’t take much contamination to keep the check valves in the pump from closing sufficiently to get pump action
Maybe the problem is just a tiny bit of crud in the pump keeping one of the valves from seating which would severely limit fuel delivery
If it was me based on what you describe
I would remove and clean the pump and reinstall
And if that fixes the problem
Move your filter to front side of pump
The fuel pump is nearly as delicate as the carburetor to contamination causing issues.
-s
