Block callback order of execution issue

I am attempting to run a simple simulation with a few blocks, all of which have callbacks at start and stop of the sim. I gave the block priorities (and I see the order of execution is the one I want), but said callbacks execute in a different order.

For what I am trying to achieve, I need the callbacks to execute as well in the same order. How can this be determined? Or, what is determining the callback order?

Thanks!

[Saumya Goel]

I am assuming that you are using Subsystem Level Block Callbacks. I have tried out atomic Subsystem with Block callbacks, and the callbacks seem to execute in the order of the priority assigned to it. I am attaching the model which I have executed. In this model, Subsystem 2 has priority 1 & Subsystem 1 has priority 2, and the associated startFcn callbacks specified with them are behaving in an expected manner.