OK, I do not see the whole model so what I say here can make and make no sense.

I am assuming you have one well producing. I have no clue if there is an aquifer attached etc. But what caught my eye was that the 9-pt WBHP for second shut in is higher than for the first. I would expect the surrounding blocks to be pressure depleating with time, as we can see that the rate is dropping. Hence a buildup should not give me a higher pressure than in the past unless something in those 9 cells is entering to give added energy.

Can you describe this model a bit more, maybe a screen capture of this well and what is around. What you give us can only make us sit and imagine.

PS: From your first post I think my statement "I am assuming you have one well producing." is wrong.