This is what I think has happened here: the gun has a safety feature that won't let it fire with an open bolt.
Part #64 (disconnector) is a punched sheet metal lever that turns on bushing #65; when the action bar assy moves back cocking the hammer, it pushes down the front cam of #64, lifting the rear cam and the trigger bar (#52), disengaging the trigger.
When the action bar returns forward at the end of the cycle, the front cam of #64 springs up, the rear goes down together with the trigger bar and the hammer can be released by pulling the trigger.
Excessive crud and residue accumulation combined with improper lubrication caused the seizure of the disconnector or trigger bar which in turn disabled the trigger. It would be interesting to know how this happened as the bushing is free to rotate on the pin tube (#66) and into the disconnector's bore as well.
First and foremost, not after every shooting but at reasonable intervals (common sense and volume of shells fired dictates this) take the whole group apart, clean and oil it and it won't let you down.
Good total productive maintenance principles: cleaning, oiling, tightening bolts.
Spray the trigger group with whatever cleaner, then with whatever oil without tearing it down and cleaning it properly, and you have a non firing gun on your hands.
The best cleaner is the automotive carburator cleaner spray (WD-40 will work too) that softenes and disolves ANY crud; but again, just spraying it on won't fix your problems, take the darn thing apart, clean it and lube it properly (use the schematic to put it back together if need to and try not losing any parts).
I don't believe the air tool lube is good for guns; at least on the MP-153's bolt and action bar you need an EP (extreme pressure) oil, like the ones used in standard car transmissions. A good industrial waylube on the slides in the receiver and action bar will work well. Even canola oil will do, but you will have excessive wear and tear in the long term, and the bolt sees some extreme pressures and acceleration.
I use a sticky lube made by Castrol for motorbike chains (has molybdenum disulfide in it) on the bolt, in a very thin film and dry lube on the trigger group. Excessive oiling won't do any good other than collecting dirt, use a thin film.
I only use gun oil for the barrel and gas system and the gun works well.
Some pictures added:
Cocked and ready to fire
Cocked but trigger disabled, gun won't fire.
Closed bolt, the disconnector's head cam is up on the edge of the action bar cocking slide; trigger is engaged and ready to release the hammer.