difference between 4.8.10 and 4.8.12

[Thomasb81]

Hello

My script is giving me different result , by changing z3 version ... and I am not able to identify change in the release note explaining it.
test3.py.zip

using z3  4.8.5
problem is stat: sat
maximum value for param1: 32
maximum value for param2: 31

using z3  4.8.10
problem is stat: sat
maximum value for param1: 0
maximum value for param2: 31

in version 4.8.10, if I switch line 34 and 35 to

max_param1 = opt.maximize(param1)
max_param2 = opt.maximize(param2)

I get back the expected result. But it make no-sense. The search of maximum value of my problem should be agnostic of the order of my problem declaration, right ?

using z3  4.8.12
problem is stat: sat
maximum value for param1: 32
maximum value for param2: 31