I believe I saw a YouTube video done by California Time some time back in which he explains that on a trip to Scotland, an alert came up on their Cali dashboard saying that the oil level was too high, & if I understood correctly, it turned out to be because they had switched their engine off during one or more DPF regens, and instead of the deisel going onto the DPF to spontaniously combust for the regen process, it presumably slowly drained down past the pistons & into the oil in the crankcase.
However, to confirm this is all true, I would want to speak to a VW expert engineer. I have downloaded the app, I have the Carista dongle, & am looking forward to giving it a go
.