Hi reddit.. can anyone please identify this tree for me? It was probably 10m tall.

Brisbane, Queensland. There is gel/sap coming from several spots around the trunk and one branch. We realised the base of the tree has become all soft and was easy to dig out. The two big dark spots on the trunk sound hollow when we knock on them. The tree never has water sitting around its base and the soil seems to drain well although it has been raining a lot the last few weeks. Only other major thing that’s happened near this tree in the last 6 months is that we removed a very large tree that was shading it about 20m to its left. Really need advice on how to treat this tree.