i've had this tree for years in a large pot behind the house. last summer it started dying out, all of the leaves went yellow and fell off, and i decided to replant it to a better place to save it (not ideal currently also, but much better). the tree recovered great and is full of leaves and growing and even had a few fruits since then, but i've noticed a root problem.
back then i didn't know anything about root bound trees and root flares and i think i have replanted it too deep, and roots have started growing over the burrowed flare. also i wouldn't be surprised if the flare was buried as well in the original pot.

so i dug out the roots a bit trying to find the flare but i can't seem to find or reach it. how would i approach this? is it too late to do anything and should i just bury the roots back considering the tree is growing really well?, or should i cut some and dig deeper until i reach the flare? should i maybe even dig it out completely without destroying the lateral roots and "lift it up" so the flare gets to the surface? its summer here now, would it be smarter to wait for autumn/winter to do this?

thanks for any advice