Yeast stopped yeasting

Hi all,
I'm new to meadmaking and would like to get some ideas.
I've got 2 melomels going, a peach and a pineapple.
They started at 25 Brix (Peach) and 18 Brix (Pineapple)
I started the mead on 1/8,
(EDIT) - Using Lalvin K1-V1116 Wine Yeast
Added nutrient (Fermaid O and K) at beginning of fermentation and about halfway through
The bubbles stopped a few days ago so I've been taking readings the last three days
The Peach is sitting at 9 Brix
The Pineapple is sitting at 7 Brix

I'm guessing the yeast died or went dormant somehow?
Looking for fixes or ideas as to what went wrong

I have another one (Triple Berry) going that I started the same day, that is nearing 0 Brix, just to add to my confusion.

Thanks in advance!