diff --git a/src/libslic3r/PrintObjectSlice.cpp b/src/libslic3r/PrintObjectSlice.cpp
index 4454ce87ea..07ba2c63af 100644
--- a/src/libslic3r/PrintObjectSlice.cpp
+++ b/src/libslic3r/PrintObjectSlice.cpp
@@ -322,20 +322,31 @@ static std::vector<std::vector<ExPolygons>> slices_to_regions(
                 }
             } else {
                 zs_complex.reserve(zs.size());
+                // region.bbox is computed in pre-belt-shear slicer space (see PrintApply.cpp::trafo_for_bbox).
+                // When belt transforms are active, layer Z values are in post-shear/scale/remap space,
+                // so the Z components of region.bbox aren't comparable to z. Skipping the Z filter here
+                // pushes those layers into the parallel_for path below, which handles multi-volume
+                // clipping per layer without relying on the bbox Z range.
+                const bool bbox_z_in_layer_frame = !(print_config.belt_printer.value &&
+                    (BeltTransformPipeline::has_shear(print_config)
+                        || BeltTransformPipeline::has_scale(print_config)
+                        || BeltTransformPipeline::has_preslice_remap(print_config)));
                 for (; z_idx < zs.size() && zs[z_idx] < layer_range.layer_height_range.second; ++ z_idx) {
                     float z                          = zs[z_idx];
                     int   idx_first_printable_region = -1;
                     bool  complex                    = false;
                     for (int idx_region = 0; idx_region < int(layer_range.volume_regions.size()); ++ idx_region) {
                         const PrintObjectRegions::VolumeRegion &region = layer_range.volume_regions[idx_region];
-                        if (region.bbox->min().z() <= z && region.bbox->max().z() >= z) {
+                        if (!bbox_z_in_layer_frame || (region.bbox->min().z() <= z && region.bbox->max().z() >= z)) {
                             if (idx_first_printable_region == -1 && region.model_volume->is_model_part())
                                 idx_first_printable_region = idx_region;
                             else if (idx_first_printable_region != -1) {
                                 // Test for overlap with some other region.
                                 for (int idx_region2 = idx_first_printable_region; idx_region2 < idx_region; ++ idx_region2) {
                                     const PrintObjectRegions::VolumeRegion &region2 = layer_range.volume_regions[idx_region2];
-                                    if (region2.bbox->min().z() <= z && region2.bbox->max().z() >= z && overlap_in_xy(*region.bbox, *region2.bbox)) {
+                                    const bool region2_in_z = !bbox_z_in_layer_frame
+                                        || (region2.bbox->min().z() <= z && region2.bbox->max().z() >= z);
+                                    if (region2_in_z && overlap_in_xy(*region.bbox, *region2.bbox)) {
                                         complex = true;
                                         break;
                                     }