CompoundCurve is a tipe of aggregate.
Use Deaggregator (flatten one level or all levels, whichever suites you better) followed by GeometryRefiner and, if necessary, ArcStroker, in this order.
@caracadrian
I have used Deaggregator one level and all level and the issues persist , this is the combination used
GeometryFilter
GeometryValidator
ArcStrokcer
GeometryRefiner
Deaggregator
Can you post some sample data?
This usually is tricky but has a stupid easy solution. The order of the transformers matters (GeometryRefiner then Deaggregator or viceversa), the validity of the geometry also is particularly important, but it's always a different solution.
Also, keep in mind we are in opposite time zones. It's almost bedtime in Bucharest😁