Did you notice that the 'payload' (1723#) dropped to just 1200# (7200# truck GVWR minus 6000# truck weight)? Subtract that tongue weight (840#) and that leaves you with 360# of payload/GVW.
Hopefully the trailer was loaded camp ready when you weighed?
And that the tow rating of 9600# is unrealistic?
With that 6840# trailer you have run out of truck (with wife/boy and anything stuff they put in truck).
MFGs numbers and real world actual numbers never match up
Same holds true for 250/2500, 350/3500 etc.