For some reasons, my commercial planes are all stuck and grounded because Jet A1 is not refueling.
AVGAS is fine for GA planes.
I have my fuel trucks and tanks ready
Did you remember to enable Jet A1 refueling in the operations screen? You have to explicitly enable it after buying the fuel depot / truck(s).
Yes I did 
are your trucks getting to destinations? i recently had a save where the fuel truck was stuck.
If your trucks are stuck… Press F10 and then Click “Clear vehicle nodes”. Its breaks dead-blocks.
Also make sure you have a Jet A1 truck.
Or simply reload the game.
Did you get a delivery of fuel? I didn’t and had to specifically request one which I didn’t have to do with AVGAS.
Guys, I have fixed the issue by turning the Jet A1 Supply - On and Off
Same here. Been away for a few days - game was fine before the break. Brand new airport created today. Avgas truck refuels happily as required. Jet A1 trucks get stuck halfway out of the vehicle depot. F10 menu makes no difference. Deleting and repositioning the depot makes no difference. Switching airport Jet A1 off and on also no effect. Reload doesn’t do anything. Frustrated right now but hope it can be sorted in future release as it’s unplayable as a result.
I have no idea but the problem is probably similar. I have tried replacing the service roads and fuel depot but the Jet A1 fuel trucks which carry fuel to my depot (the yellow ones) doesn’t come in from the spot check in stop (I forgot) and left. I have no idea