OP glad you got it solved. I'd have suspected the starter or loose connection since the inconsistent starting was tied to physical movement and parts. Probably would have tried to get the starter exchanged vs taking the whole tractor in. But that's what is required during the warranty so their hands do the work.
No matter, old machines break too. The first year owning my 18yo 255k mile truck was spent tolerating a charging issue. After a marathon day of diagnostics on each component top to bottom, and replacement of those worn out parts, it's fixed.
Anyway, congrats on your new tractor, I bought my MT242 this year too. Old machines start out new at one point.
Oh, regren, my first was at 17hrs, then at 27 and 33. The 33hr one ticked me off. If regen is a result of the soot production and soot is high, seems the tractor is not hot enough or fuel is too much. I'm running my tractor in 100*+ weather @1700+ idle and 22-2500rpm for several hours of work. I didn't agree a regen should occur in those conditions. I've also noticed from the beginning my tractor's temp gauge stays low. Which seems odd to me for those conditions.
Am I not working this tractor hard enough? Is the thermostat compromised? Is the computer at fault? Don't know, but I'm watching. I've toyed with the idea of installing a 'winter front' to see if that affects the temp gauge reading at all. It should, especially n the summer. And if it doesn't, is the cooling system more robust than I think, or is it faulty? IDK, but those my thoughts.
At this point in time, on this specific property, my tractor may very well not be getting the workout it is capable of tolerating. If that's the case, I'll work it hard when I use it. Since the 33hr mark I've bumped up my idle rpm now to 19-2k after a brief wake up idle to get the oil flowing. Work rpm is still 23-25. I'm curious and waiting to see when the next regen cycle occurs.
But again, every old machine was new at one point. Takes time to break a machine in to really see how it'll be. You don't know long term results until you get through the long term time.