I don’t understand what you are doing.
You are summing (adding up) all of your Monitor Sources.
In normal conditions, you have one (1) monitor source selected.
That’s your (default) main buss out. That’s where your main mix resides. That’s what you are exporting as “final mix”.
The other “Sources” are meant to audition stems, MX, DX, FX, etc …
The whole point of being to summ these sources is to listen to the DIAlog and -for example - foley, omitting the other stems.
I really don’t see what you are trying to achieve, but I can tell you that it is a remedy for disaster.
Fredo