The right tool for that occasion would be a watchpoint.

1. You check in both places in code in the debugger that the address of the field matches. (Maybe the object is at the same address, but due to some build system level ifdef mismatch, you effectively get different struct definitions in different places or something like that.)

2. You add a breakpoint inside the procedure and outside it.

3. When the breakpoint inside is hit, you add a watchpoint at the address of the field. Continue. See if the watchpoint gets hit before reaching the second breakpoint.