My 2020 3500 goes into regen every other day, probably 100 miles give or take, I had problems with it about a year ago, the dealer had to replace the CAT and the DPF filter, it was under warranty at that time, after was told to drive it hard on the freeway every now and then, which I do, but now it seems to regen more often, the truck does not sit in much traffic, so it can't be that, maybe it had an update the last time it was at the dealer, anyway I am worried about it, it never used to do the regen that often, I keep the DPF gage up on the screen, but even when it is driven hard you can see it go up quickly, the truck has 30,000 miles on it.