Feeding is actually two things:
– getting material to extruder
– the extruder swallowing the material to then melt and extrude

These two things are commonly called the same thing. ‘feeding’.
Troubleshooting them is very different, thus we would call them:
– getting material to extruder = ‘transport’ feeding
– extruder swallowing the material = ‘actual’ feeding

Start with the actual feeding :
– temperature too hot, material melt in feeding
– material doesn’t roll or flow inward
– chamber is not full, disrupting pressure generation

And transport feeding :
– material bridging in any point
– materials doesnt roll or flow (also leads to bridging)

What is bridging? (See : bridging)
Essentially material clung onto surfaces of the path, and builds up one another like how cholesterol builds up in the vein.
Then it creates a blockage that resembles a bridge.
The bridge is usually breakable by poking it but would create itself again right after.
The issue here is caused by a combination of non-smooth path and a material shape that hardly rolls/flows.