V8 Transmission changing problem

Hi everyone.

I bought few months back this car which had broken automatic transmission. I washed the transmission from inside carefully with diesel oil and then I changed the A and B clutch plates which were totally destroyed. Then I changed oils and put the transmission back together. Now the transmission runs ok and I have been able to drive with it, the problem before was that the transmission was sliding badly,

now it is not sliding anymore but sometimes when I change the gear it does not change correctly, like when I put P in it will only go to R or N won't go in easily, or when using manual gears 1 goes good, then when I change to 2 it wont change but then changes to 3. Sometimes when driving with D or setting of from 0 Kph the transmission feels like it had wrong gear in.

It started to feel better when driving like 10 kilometers but still it feels a little not good. I have another "Multifunktionsschalter" so should I try to change this or could the problem be it the electromagnet which tells the position of the shaft?

If I am changing the Multifunctionschalter should I change the transmission control box too or does it communicate with new part without coding?

Kind regards.
-Rauli

PS. Thank you from your answers in advance.