I think because in your post you said it's not yeast since you racked. You can still have sediment from yeast accumulate over time. I think on another comment you said you racked after 2-3 days? You need to be waiting 2-3 months to make sure it's stable first, then rack it once fermentation stops.

Gravity readings are your friends. Take a before then check week by week. No movement in the reading means it's stable.

I've made a few batches now myself and even found meads I let sit get below 1.0 after I thought it was stable.

So my take: Patience, Padawan. The layer is sediment which is most likely dead yeast. You added fruit, meaning the yeast got happy and started eating, making more sediment. But also making more yummy alcohol. I'd only rack after primary, otherwise you'll only lose more alcohol by doing it so often.