A bit more information would have helped here, I assume you’re referring to your Great Vault choices.
Could you link to the logs you got that result in please?
Which trinket did you change?
I’ve spent a bit of time looking at this and I’m not seeing that, so we’ve got some different settings happening.
4,780 DPS equipped gear in your snapshot.
4,801 DPS equipped gear with top trinket changed.
4,677 DPS equipped gear with bottom trinket changed.
Here it’s worse changing the bottom trinket and a tiny bit better changing the top, 21 DPS is well within the standard deviation and not even double the error margin, your current setup got a higher max too.
I then simulated the BiB result, it changes the legendary and also your soul bind.
4,945 DPS BiB
4,923 DPS BiB with top trinket changed.
4,834 DPS BiB with bottom trinket changed.
With the best in bag result it isn’t an upgrade either, changing the top trinket is closer but they’re so close you’d never be able to tell the difference in game.