Gearbox warning light, but my obd-ii says it's a dpf problem
 

I have a manual 2010 Mazda 3 1.6d. After changing into fourth gear yesterday the car lost tons of power, especially in higher gears and low revs, and the gearbox warning light lit up. I managed to finish the drive to work, and when I started up the car afterwards the same issues was there, only now the check engine light had lit up as well. After connecting my obd-ii reader, I got a P242F code for DPF restriction due to ash accumulation. The DPF warning light never lit up. Has anyone experienced anything similar? Any idea what's most likely to be at fault here?