The grid will fit in with the clues if you just add in two horizontal bars.
One is under the box currently marked 5, which moves 5 down one box rightward and creates 12 down (one box to the right of where 12 is currently printed).
The other bar symmetrically paired with that one, which makes 16 down correctly a 7 letter word finishing just above the bottom row.
With those two bars in place, 11 across renumbers as 10, 12 across renumbers as 11; from then on across are OK.
The down clues are in the right order but mis-numbered between 5 and 12 inclusive. 16 down is correctly started, but wrong length, and thereafter the down clues are fine.