I'm far from brand loyal and over the last 30 years (in order) have owned Toyota, Ford, Nissan, Chevy, Honda and now my Ram. Unfortunately, the Ram has been the least reliable and most notably the tranny. And I don't mean just my experience since obviously, I singularly, mean nothing from a statistical/scientific sense.
Ram trannys pretty much suck and have for decades. I remember as a kid working at a service station back in the 80s listening this Dodge fanboy bragging about how he got 90K out of the tranny on his LeBaron. Even as a dumb kid I knew that was nothing to be proud of. I suppose the 68RFE behind (most of) the Cummins is a a bit better than the 66RFE behind my 6.4 Hemi. I base this on a totally non-scientific study of the posts I read here. The Duramax/Alison tranny in my 06 Chevy was bullet proof and ran like a champ through 150K when I sold. I hung out on Chevy/GMC message boards and can't remember more than one or two problems. Ram? Failures on Ram trannys are very common. Any time spent on this board will tell you that. Valve body failures are most common. My tranny failed and was rebuilt at 38K and 90K and is holding at 130K but shudders and clunks at times. If not for my Lifetime Warranty I would have certainly offloaded this truck for fear of repairs. My engine also failed at 120K but is another story and not something you are asking about (and was a Hemi not a Cummins).
Having been through various vehicles and experiences over the years I have zero interest in owning any FCA vehicle without a warranty. Almost forgot my other data point... the tranny in my company's delivery vehicle - a 2020 Jeep Cherokee, failed initially at 40K but was limped to the dealer and miraculously healed (wouldn't replicate the problem) but then finally failed at 62k.... just as the engineers planned it with the 60K powertrain warranty. Luckily, I had another extended warranty and got it rebuilt.
Lastly, I live an ocean away from my Ram truck and only drive it a week or so every month or two (moved to Maui from Oregon) and my daily driver here is a 2008 Honda.... never a hint of a problem in 15 years of ownership. If only Toyota or Honda would make an HD truck!!