Just to clarify if other members have experienced these VNAV descent issues:

1) Speed constraints are not adhered to when input into the FMC for a waypoint in the descent phase (Screenshot 1)

2) Selected speed (SEL SPD) in the VNAV descent page does not function; the speed bug on the tape is erroneously increased no matter what input is made (Screenshot 2)

3) Speed restrictions (SPD RESTR) are not followed when the user inputs an entry to the VNAV DES page (Screenshot 3)

These entries appear to work fine during VNAV CLB and CRZ but the DES page is very unpredictable.

Please find the screenshots attached in the following posts: