Jet pump / transfer pump troubleshooting

[g300d]

So I stalled at a light today in the 4.6is. Felt like a fuel issue. Gauge a bit below 1/4.

Checked OBC and 0 fuel at the right side and about 14 liters on the left. Called a friend to bring me a couple of gallons of gas and ended with about 7 liters on the right. X started instantly.

Drove straight home to change cars while watching the OBC. Fuel level on the right was varying especially when going up the parking ramps but didnt drive long enough to verify jet pump operation.

Any tips on troubleahooting thia problem? Jet pump was replaced maybe 5 years ago.