Outback diesel particulate filter problems

[Gabrue]

Hi, my dpf light has come on a couple of times recently (2016 model, recently purchased), although I'm hardly ever in any traffic and it gets a good run every 2 weeks. 

I went through the regen process as described in the handbook, but it came back on soon after. The car has 33k miles and was very regularly serviced.

Who knows about the 'engine oil dilution' effect,as described by Bart at MRT Performance. Is that a common problem? TIA Gabs