I have had these nonstop problems with my D. Adelae that pretty much prevents it from maturing.
I got it from @Staats+17+ wayy back in late May as a bigger seedling. It hasn't grown an inch since I got it, even though I feed it once or twice a month...
It also keeps dying off and producing 1-2 new plantlets from the roots which then mature as big as the parent plant got and ultimately die off and do the exact same thing. It's been doing this for the last 5 months I've had it and I can't seem to fix it.
I kept it in a ziploc bag for a while before ultimately acclimating it to 50 percent indoor humidity. It has been doing like crap since then, blackened growth and wilting.
I keep it at the moistness you grow Flytraps in, and it is growing in live sphagnum. Pic below.
Thanks and so sorry for the long post but I still hope someone reads this,
Dionaea M. 'Fused Tooth'
Dionaea M. 'Alien'
Dionaea M. 'Scarlatine'