Hi @SimQARobo,
I had this glitch in early March and lost the save data due to my HDD crash. All I can do now is remembering my situation, but I'm pretty sure I didn't use the cheat code, because I'm not familiar with those codes.
1. Did the affected Sim have the Run Run Run buff when this occurred?
I'm sorry, I can't remember if my sim had or not. I didn't pay attention to her moodlets, but her toddler trait had been Wild, so she could have it.
2. Was the Sim ever a toddler?
Yes, I first made her in CAS as a toddler and a daughter of my main household's collateral family. I basically didn't play the collateral household.
3. If so, how did the affected Sim age up from Toddler to their current age?
She automatically aged up in her original household while I didn't play. I had not played her at all while she was younger and living in another house, but after all she got married with non-biological son of my main family and moved to the main household, then I noticed her toddler walking.
I didn't play her directly but I once tried to call her up to my main house as a friend when she was a toddler, and before she left, she played wrestling with an active sim. So, she might maintain that moodlet after that and eventually got older with it.
In either way, I think "automatically grown up in inactive household" could be somehow add to this glitch's conditions, as well as the cheating.