Selective Jettison is not working at all for me, at least not for centerline tank and pylons (i honestly never tried on the fuselage)..
I am completely aware that this is functioning as intended for the majority of the people.
As far as procedures go, here's a video of yesterday's flight displaying the behavior with the CTR tank (including F2 view checks to confirm the issue is still persistant for me).
Just watch the next 30secs - 1min from timestamp (46:46) and disregard the rest of the video:
System is Ryzen 5 1500x @ 3.9, 16GB RAM @ 3066, 1050TI, nvme for OS and regular SATA SSD dedicated to DCS... if you need more info please let me know.
EDIT: i don't know how to embed that video here, sorry about that (feel free to let me know and i'll fix it)