Transgo TF2 on a 904 is not shifting

We changed the gov 12 valve as the picture.. we saw that the valve was tight... we sanded it a little bit... and it entered.. on the lift the car changed from 1st to 2nd and to 3rd... after some tests it stops to go forward... reverse always engages.. but forward nothing occurs in drive and 2nd or 1st.
Before of valve change... it was engaging normally 1st gear...
Something came on my mind... maybe the valve is still tight then when starts getting hot it is expanding and getting stucked? This could cause the car stays stooped on drive?