Well, in case anyone has the same issue I experienced let me save you the headache.
In case you have done every possible thing and some engines start-up and others don’t while you are following the same procedure try this:
1-Open the tablet
2-Go to the maintenance page
3-Repair your engines and check your fluids
Turns out I had an issue last flight and two of my engines died (I forgot to remove the interlock and gust locks and overstressed the 2 unblocked engines), and apparently, the wear and damage you suffer on your plane is persistent between sessions, so my engines were still broken on my new flight.
It took me 1 hour and the help of a subscriber of my twitch channel to figure it out, soooo I hope it helps someone as id1iot as me xD