GSX setting planned fuel message and no fueling

[AviS]

Good afternoon!
I have an issue with PMDG 738, please help me solve it.
The last updates were installed, but I've seen this issue before a lot, so updates are not crucial.
After GSX is started, and the Simbrief plan button is green (I press it once again to see that it is correct), I ask for Refueling.
The truck arrives and I see "GSX setting planned fuel" msg. I can see the correct fuel amount is set by GSX and after that, the fueling starts only in 1 of 5 cases. I don't get why. I have to click randomly on the fuel page and set random amounts of fuel to start fueling. It is annoying indeed. If fueling doesn't start then this msg will appear indefinitely.

[virtuali]

I have to click randomly on the fuel page and set random amounts of fuel to start fueling. It is annoying indeed. If fueling doesn't start then this msg will appear indefinitely.

Be sure the FMC scratch pad is clear of characters (unfortunately, there's no way to clear it automatically with the PMDG SDK), because if it's not, the automatic key input won't work.

[AviS]

As I mentioned in the first post, GSX successfully sets the correct amount of fuel according to the flight plan via FMC, but the fueling with the truck, that supposed to start after that, starts in 1 case of 5.

[virtuali]

I can't reproduce the seemingly random failure. It starts 100% of the time here. If it isn't for you, please provide a diagnostic log of a failure session.

[ssprinted]

Make sure your apu and fuel pumps are off..

[iiBus]

Most flights I've also got this problem - even with everything off except batteries, emergency lights and ground power. Occasionally it works.
It enters the fuel into the FMC as expected but then gets stuck on 'setting planned fuel'. Occasionally I've been able to sort it by re-entering it myself, but with a decimal point (10201.1 for example) but most times I end up having to override it by setting it to a slightly higher value. I've not checked but this is happening on Ryanair variants which have fuel input entered as kgs while the simbrief plan its referencing to is in lbs.
When doing a turn around, it almost never works, but I do have APU active when requesting fuel so that is probably why. Is it not possible to check if the fuel is within a range of the value (i.e within 50kg)?