[DK on the road]

John, last year I had a similar experience while driving into Twin Falls ID. It ran at fast Idle, or rolling down the road at speed, but below 800 RPM it struggled and eventually shut down. My Bowl was empty after sitting or it shut down. It was hard to restart, due to loosing prime.
I spent a lot of time looking for glittering Unicorns before getting back to basics and getting logical on fuel supply. I thought my lift pump had failed, I was testing pump pressure, repriming filters, etc. it wasn't getting consistent fuel.

I Pressurize my fuel tank with 3-5 psi to a open line before fuel filter. I had a loose fitting above my fuel tank that allowed enough air at low speed and not enough fuel to keep it running. After shutting down, the pickup line would slowly lose suction and prime. The air pressure showed bubbles at the fitting, and I heard the PSSS.
Simple fix, but I spent 6 hrs trying to figure it out. But that's me.

Hope it's this simple.