Deposits?

I believe we need a little better information on why a 15W-X is making/allowing deposits in 2019+ engines where a
synthetic 5W-X isn't. Is it the word synthetic? A casual search doesn't turn up any 5W-40 Conventional Diesel oil.
This TSB appears to also update older 2018 on down to "Require" rather than "recommend" 5W-40
Synthetic oil below 0F. My 2018 Owners manual has "Recommend" in it rather than require. I can't imagine this synthetic expense, higher TCO, is going to go over well with fleet managers.
Related ... Perhaps my selling dealer switched to all diesels get 10W-30 so it's un-possible to screw up a 2019+ Cummins.

Unexpected finding with UOA, but, this is why I spend the money on them. It's possible the dealer oil sheared down or (unlikely) is contaminated with Biodiesel from an unlabeled diesel pump here.
It may be a good idea to run the 5W-40 synthetic option on the 2019+ if you have to use higher Biodiesel blends than 5% due to: availability, new laws mandating higher %, whatever.
@AH64ID I suggest this is why FORD note (2) has "use" higher weight oil for B20.
I do know UOA does not show Biodiesel as fuel contamination (Rather it can show the loss of viscosity from Biodiesel in the oil), but, I avoid high % of Biodiesel anymore after my past bad luck with it. When adding Diesel one should read the labels on the pump as this one claims 5% or less Biodiesel.
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The two UOA in red were my selling dealer oil changes, one free from FCA. FYI Mobil Delvac 15W40 is the 22,031 mile oil sample. I do not recommend switching brands when doing UOA trending. Due to unavailable Shell T6 I am forced to switch, yet again, where Mobil would have been the odd one out. Low miles on oil due to 6 month oil change requirement on my 2018. I did like the low wear numbers on the T6 combined with engine likely broken in now.
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This is what the dealer paperwork said was supposed to be used...
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