I have 4 cells that Solver is supposed to change to minimize the value
of one target cell, where the target cell sums a bunch of rows that
have changed values depending on the 4 aforementioned cells.

Whether I click min or max in solver, it says it solves the equation
fully but the results do not change for min or max compared to the pre-
solver values. To test if it was working, I (in short) click for the
solver to find an exact target value I know for a fact exists locally
(and required only changing one cell value), but Solver says it cannot
find a feasible solution.

All of this tells me that the proper operations or operation sequence
is not happening during the execution of solver. I thought I'd fixed
the issue at first, when I rearranged the involved formulas so that
everything was on the same Excel sheet, but it didn't work.

Are there other Solver limitations I need to know about that could be
causing the issue? I was surprised that Microsoft Support and the
Solver Help file did not mention that I need to have all formula
references on the same tab, and so am concerned there's other
limitations I am not aware of.

I have tried changing all Solver Options too, but no help.

I will try to simplify the involved data below:

Solver changes these constants...
Cell A2 = 0.31
Cell A3 = 0.25.
Cell A4 = 0.67
Cell A5 = 0.52

to minimize the value of a target cell with the formula:
=SUM
(D41:E2000,I41:J2000,N41:O2000,S41:T2000,X41:Y2000 ,AC41:AD2000,AH41:AI2000,AM41:AN2000,AR41:AS2000,A W41:AX2000,BB41:BC2000)

The columns summed in the target cell formula above have their own
formulas. An example would be:
=IF(AND(C41<A$2,C41<((A$6*B41)+A$9)),1,0),
where C41 and B41 are constants I am not changing in solver, A$2 is
one of the constants I am changing in solver, and A$6 and A$9 have
formulas that reference some of the constants I am changing but are
not directly inputted to the solver.

Thus, solver changing any of A$2 through A$5, will change A$9 and/or A
$6, which in turn changes the column values that are summed in the
target cell formula, thus changing the target cell value.

Thanks for any help,
K