Strong deviations in between waypoints

[RobertVdb]

Hello,
The path of my aircraft suffers from strong deviations in between two waypoints. It doesn't fly straight but always describes a small arc with a kind of sinusoidal correction at each waypoint (sidewind or not). It happened suddenly a while ago, and I am not sure if it is directly related to the CDU. Can somebody help me in solving this problem?
Thanks
Rob

[AK Mongo]

If they are long distance flights, you may be flying a circle route. Beyond that, no clue.

[RobertVdb]

No, Mongo, the waypoints are sometimes only 40nm away from each other.
I have read in a post here that a duplication of an afcad file with different mag directions can cause this. I am now checking that.
Does anyone know a better program than scanafd to find that out?
Thanks
Rob

LATEST INFO: seems to be solved by deleting some double AFCADs