Well, we finally found out what it was
Guess what
Faulty sensor it was, crankshaft position sensor rusted, held up just until you warmed it up and after reusing the car since then, worsenned even further
We also suspect oil pressure warning to be the sensor too, and seeing how it's just next to the crankshaft one, no detective work needed to figure it out, they both rusted, which is angering how it could happen but whatever, case closed at least
At this point, when it's German or recent, check if the sensor is doing its work before doing anything else.
Yea it was crankshaft sensor being done,