Hello sir:
Proud to help, I hope all is fine otherwise with you.
Sounds like you'll find a bit rust or other contaminants impeeding the flow of fuel through the tank filter. When you drop your tank filter be ready with 2 three gallon basins to comfortably catch the remaining fuel. with a light and extension grabbing tool You'll be able to fish out the small round bottom plate(lost) and observe that rust or maybe bio-contaminants which is less likely(haning coated smoothly and sometimes evenly surfaces yellowgrey to green in color) or both have gathered near the tank sump and on the tank filter.