source/blender/editors/transform/transform_convert_nla.cc

@@ -730,7 +730,10 @@ static void recalcData_nla(TransInfo *t)
     delta_y2 = (int(tdn->h2[1]) / NLACHANNEL_STEP(snla) - tdn->signed_track_index);
 
     /* Move strip into track in the requested direction. */
-    if (delta_y1 || delta_y2) {
+    /* If we cannot find the strip in the track, this strip has moved tracks already (if multiple
+     * strips using the same action from equal IDs such as meshes or shapekeys are selected) so can
+     * be skipped. */
+    if ((delta_y1 || delta_y2) && BLI_findindex(&tdn->nlt->strips, strip) != -1) {
       int delta = (delta_y2) ? delta_y2 : delta_y1;
 
       AnimData *anim_data = BKE_animdata_from_id(tdn->id);