OK, I ran them again. The proper comparison here would be:
best in bags solution (5081 dps): https://www.askmrrobot.com/wow/simulator/report/3624d9fdeeda456ba9f987eb5abd9d84
best in bags solution with your current trinkets locked in place of the suggested trinkets (5140 dps): https://www.askmrrobot.com/wow/simulator/report/51b89a4fc9d044b9ab3c4916421fafcb
(another option is this, with soulletting ruby and satchel: (5119 dps, very close to your current gear) https://www.askmrrobot.com/wow/simulator/report/62f607c97be04736af98d4724226d5ef
I think what’s happening is that the unbound changeling is ranking a bit too high… that is a weird item that gets its special effect from a bonus (there are 4 versions of it), so maybe something is going on with it.
The fact that the optimizer slightly prefers the soulletting ruby to some of the other on-use options isn’t a big deal – the different is so small it doesn’t matter. So with your settings it will pick one on-use trinket (probably the soulletting ruby), and then it should pick a better non-use trinket, like the satchel. I’ll look into why the unbound changeling is ranking too high.