I had this happen a few times during the NPE, so I'm not sure if it's because of something in the NPE or happens in freeplay and I don't use burner inserters enough to notice.
There was plenty of coal available on the belt, yet the burner inserter would run out of fuel.
[0.17.64] Burner inserters running out of fuel when fuel is available
Re: [0.17.64] Burner inserters running out of fuel when fuel is available
Most likely "Not a bug", as burner inserter is just another type of inserter.
Inserters have priority on near lane, and so in you case inserter run out of fuel because it failed to grab coal from far lane, and that is because it was occupied transferring copper ore from near lane.
I think it could have been done better: priority 1/fuel for itself from near lane, 2/ fuel for itself from far lane, 3/near lane, 4/far lane. This would solve this particular case.
Another solution is to "keep it as it is" so they are little annoying to force player to handfeed them (sometimes when they fail) so they feel little unreliable and to force player to look for other solutions (like electric network and regular inserter that is a lot more energy effective).
In most cases they dont need to be hand fed as long as they start with grabbing some fuel before there is incoming copper ore or other stuff
Inserters have priority on near lane, and so in you case inserter run out of fuel because it failed to grab coal from far lane, and that is because it was occupied transferring copper ore from near lane.
I think it could have been done better: priority 1/fuel for itself from near lane, 2/ fuel for itself from far lane, 3/near lane, 4/far lane. This would solve this particular case.
Another solution is to "keep it as it is" so they are little annoying to force player to handfeed them (sometimes when they fail) so they feel little unreliable and to force player to look for other solutions (like electric network and regular inserter that is a lot more energy effective).
In most cases they dont need to be hand fed as long as they start with grabbing some fuel before there is incoming copper ore or other stuff
Re: [0.17.64] Burner inserters running out of fuel when fuel is available
Post a save where a burner inserter not taking fuel even when provided can be observed please.