If the trans did what you described with the new fluid it would smell like a forest fire.
Drop the pan and post a couple of pics.
That will tell a lot.
Sounds like a burnt forward clutch to me, and possibly the front band.
Forward clutch is applied in high gear... Not first or second.... If you apply the forward clutch & the front band at the same time bad things happen....
Try increasing the length of the kickdown rod 8MM...