ChatGPT and the word "Descails"

I first encountered ChatGPT-4 using the word “descails” instead of “descends” around a month ago. I didn’t think much of it at the time, but it was the first real typo I encountered using the app. Today, I encountered it for the third time, and now I’m beginning to wonder why that happens.

With some Googling, I managed to find one instance of the word being used in that sense (or any sense) - - and I’m 90% sure that description is GPT-generated.