I really have no idea what was done at the original repot but from those last two pictures, it essentially looks like the tree is sitting in a pot with 2 completely different soil types… the original soil mass looks very organic/ peat heavy while the outer layer is large grained pumice. This situation poses great difficulties in watering as the water will move rapidly through the outer layer while barely wetting the peat, which will dry further and eventually become hydrophobic. When I repot trees in peat based soil, I tend to be very aggressive removing the soil from the entire periphery of the root ball as well as under the base. I’ll leave lots of bare rooted roots in these areas and then have the new aggregate soil worked into them. Doing this assures that there are adequate roots in both types of soil. Fwiw, my plan with that material would have been to saw the bottom 1/3 to 1/2 of the root ball off then bare root 50% of the remaining root mass so I could work my aggregate soil into the bare rooted portion.
