I am having the same problems. I am new to dcs so i thought i was doing something wrong.Perhaps iam, but it is driving me mad. The PVI coords and the Abris ones no matter what procedure i chose or editing waypoints, dont align on flight. Route mode has a drift that sometimes the abris cant recognice when I have passed a waypoint so doesnt update to the next one (even if the message sterpoint passed is showed). Sometimes there is a message in the abris "CTD limit" that i have no idea what means and it seems is undocumented in the manual. DT is hell. If i use route mode before waypoint 1, the helicopter stays above the airfield trying to hover and so on. Is the HSI or the abris working as intended?
That drift is intended or a bug? Are the developers answering those questions?
I smell there is something wrong/bugged with the magnetic deviation that is impacting the INU aligment.