Yeah i experienced that too. Wasn’t able to answer because of looping requests from ATC. ^^
But in the meantime i could fly several IFR-ILS approaches with the 320neo (stock, no mod). I found that one of the main differences in the “ATC guidance logic” compared to FSX is that you have to fly the headings and approach procedures yourself while the FSX ATC would always guide you vector by vector as long as the course was programmed as a flightplan (i.e. visible in the GPS) and IFR was chosen during the creation of it.
This very much confused me at first as i had no experience with FMC and such. I learned about the managed mode of the AP and with that the 320 followed it’s course and ATC gave me appropriate altitudes till i was established on the localizer.
May i ask you a question about this:
This worked fine in managed mode because the autopilot flew the legs and kinda “marked” them as done when i was at the end of them and then the next leg on the vfr map became magenta and so on.
But then i tried another procedure, now with the Cessna 152, obviously having no autopilot. But since you can see the procedure with waypoints and turns on the vrf map one can handfly it. But here i observed that it didn’t switch to the next leg, even though i flew the procedure very accuretly. The first leg remained magenta no matter what. Thus ATC was no giving me further instructions even though i proceeded with the approach procedure. This tells me that there has to be some autopilotsystem in use which tells the internal “ATC logic” that a certain leg is fnished.
I know, the 152 isn’t meant for IFR, but here’s another thought (i will try this later today): What if i want to handfly such an approach procedure with the 320? Will this work or not? Is there a way to mark a leg as finished in the FMC or a “manual mode”?
Edit (few hours later):
I now tried this in depth and came to a simple conclusion:
The recognition of the waypoint progression doesn’t depend on flying AP or manual, it seems to only depend whether the aircraft has a gps built in or not. I tried A320, Cessna 172 G1000 and the steam one (has a small gps) and the 787. All of them can be handflown and the flightplan on the vfr map progresses (magenta leg switches to the next when you reach the point) and the ATC works fine. You can even slew along the planned procedure with max slew speed and it works.
But as soon as there is no GPS onboard it always stays on the first leg, so the case with the 152.
But tbh i think this i pretty cool cause now i can handfly approaches and use the vfr map as a help and ATC is with me all the way. Very immersive for me 
And when i just want to look outside a little more i go back to managed mode or GPS AP.
Sorry for the long post, just wanted to complete this matter.
have a nice day