I have a 2 year, 286 hour M7060. A few days ago it started to cut off after 3-5 minutes of operation and then started again, it may work for hours.
I found a lot of crap in the water separator moving / floating around and obstructing the flow of fuel from the separator to the lift pump. I cleaned the separator, then changed the fuel filter just in case.
There is no priming pump on my sep, the service manual says to turn the key on for 30 seconds, turn off for 10 seconds, and then repeat to prime the pump.
Around the 5th time the key was turned on for approximately 20 seconds the pump overheated and died as it was cooled by the flow of fuel.
Today, the new pump in place does not prime. It only works without taking fuel out of the tank.
Your problem looks like a glob of algae. I recommend you to clean it by washing all the fuel, and then a apply new fuel filter. Add an algaecide to the new fuel. I had a fuel flow problem similar to a horselfy lodged in the banjo fitting in the supply line to the electric fuel pump. I’m not sure if your fuel line is similar. Also, I’m sure you’ve double-checked that the fuel cock has been turned back on.