Spring 2021 I bought 4 brussel sprout seedlings. 3 died, one made leaves but never sprouts and lived, thru winter 2021-2022 and 2022-2023. I still have never seen a sprout. Peeking under the leaves this is what I see? Did I just raise food for my bunny?

Never actually get the little balls, just leafy things. It's still alive and well

Brussel sprouts are a tough go in the south. Never been able to get the timing right in Georgia. Back in Virginia I had some success transplanting in July, topping in November, harvesting around Christmas. I used the shortest DTM variety I could find (Prince Marvel) and was able to get usable sprouts 3 out of four years. They needed a longer cool season than Virginia. Never able to the first usable sprout in middle Ga. I can grow most northern vegetables in the winter here, but never mastered sprouts.

you have to top them? ok. I grew rabbit food, my bunny will be thrilled. It's 2 years old and no sprouts. Thank you @farmerdill

Topping (cutting off the terminal bud) once the lower sprouts begin to form up seems to speed up the development of the lower sprouts. In my case it allowed me to get a short stick of usable sprouts before deep freezes in January and February. In Virginia's New River Valley below zero temps were common. Here we get a few temps in the teens at inopportune times but just enough combined with short daylight to trigger overwintered Brussells into premature flowering.