Your comments give more clarity. You have changed your process by now draining more wort from your boil kettle which alters the brew house efficiency (BHE).
The way BeerSmith calculates BHE is by comparing the percentage of sugars which make it to the fermenter as compared to the potential amount of sugar available in the fermentables bill you provide.
What I see in looking at your sessions tab is that you hit your gravity target from the mash, but ended up with a greater volume than anticipated by about 3.6 liters. This gave you a higher mash efficiency since you now recovered more sugar from the grains than was calculated from your equipment profile.
Next, you ended up with 21.5 liters in your carboy, but with a lower gravity than target. This added volume compensated for the lower gravity to give the same amount of sugar as your equipment profile predicted. Thus the same brew house efficiency.
Now, from your figures you should have the same amount of sugar points pre-boil as post boil. If I look at the figures, you have 29 l * 54 gravity points = 1566 sugar points. Post boil you have [21.5 l + 2 l (trub)] * 60 gravity points = 1410 sugar points. This deficit in sugar post boil from the pre-boil amount indicates that there is a measurement which is not correct. Either your post boil gravity measurement is off, you have more loss to trub than you counted on, or your pre boil volume measurement is off. You need to track this down before you make a change to your equipment profile.
If you back calculate your pre-boil volume from the ending sugar points, you get a pre boil measured volume of 26.1 L which is closer to your target value.
You will also need to address your boil off rate, since it is most likely set too high. If you started with 29 L and boiled down to 23.5 L, your boil off rate would have been 5.5 lph instead of the 3.5 lph in your equipment profile. If instead you actually yielded 26.1 L post boil, your boil off rate would have been 2.6 lph which is below the value in your equipment profile.
My recommendation would be to keep your profile where you had it for another brew. Make careful measurements and compare the values to see how much error there may be in your measurements. If you are relying on pre-stamped volumes in your boil kettle or mash tun for measuring starting water or wort, check those volumes against a measured amount of water added. I have seen pre-stamped volumes be off by as much as 0.6 liters due to variables in manufacturing or poor alignment of the engraving device.