Resawing in its thickness a plank, often of high value in case of luthiery, is never easy and the bandsaws are often capricious when you want to saw along the parallel fence.
You can see it under two perspectives:
Wheteher you spend a lot of time sharpening and setting your blade, which is of course always advisable, and you spend after that a lot of time setting up you bandsaw saw guides, as well as the upper wheel to find the correct set up until it runs straight.
Or you use a "resaw post",that allows, whatever is the angle decided by the blade, to follow it.
It is a vertical pole, fixed parallel to the blade on the fence, with the ability to slide along the fence for setting it up in front of the blade.
It is worth starting by putting on the jointer the plank side that will slide along the post.
Then you draw the cutting line on the side of the plank, and you apply it against the post.
You cut following the line, while adjusting the horizontal angle in order to follow the angle that the blade will have decided.
This is eventually a simple mean to achieve a reasonably correct result, without spending too much time setting up the machine.