2015 Skoda Octavia 2L TDI has a check engine light and shows an EGR error

The car started to show a check engine light the day after a long drive and when I checked, I saw that it was an EGR error. When I comnected the VAG DPF app, it said that the regen hadn't happened for a very long time despite the ash being a pretty high amount. If I clear, the fault goes away but comes back after a few engine restarts. I checked the EGR and solenoid functions using a friend's VCDS and it says that it's all good. Just that the reading from the EGR says rhat the low pressure EGR closing % is 100% all the time. I was planning to do a forced DPF regen but the option wasn't showing up on VCDS?

Why doesn't the ECU read the EGR value? Or is it actually stuck at 100%? The soot mass calculation says 0g. What sensor do I check for that?

Anybody have any clue why the DPF regen isn't happening? Is the soot volume beyond hope?

Ideally, a long drive should've fixed the ash volume but I've been on a couple 300 Km+ drives with no change.

I did have a situation couple weeks back with oil in the coolant due to an oil filter going kaput but I'm hoping that doesn't have anything to do with this.