Maybe you are using pygplates.Feature.get_geometry() to retrieve the geometry from each partitioned feature. The problem there is that assumes a feature has only one geometry (it will return
None if there’s not exactly one geometry).
However it’s possible that a single plate can partition a feature’s geometry into multiple geometries. For example, a line intersecting a thick U-shaped plate polygon in two places (the U then cuts the line into two small pieces where the line overlaps the U). In this case the partitioned feature ends up with two small lines and has the plate ID of the partitioning plate.
Try using pygplates.Feature.get_geometries() instead (note the plural
get_geometries instead of
get_geometry). Then you need to iterate over all geometries in each feature as in:
for feature in partitioned_features:
for geometry in feature.get_geometries():