Thanks ! I converted alembic into editable poly and it solved my issue , but anyway how comes that there is no way to bake alembic into keys ? max 2020 release was alembic improvements release also , and no baking ? or maybe it's there but I can't find it , Can you tell me how to bake alembic into keys ?
by the way max 2020 alembic bugfix table says that mesh with ngons are fixed
but not completely fixed it's make some faces bigger than "cap" would do, it still has some problems in other words . maybe it's on my side I will investigate with other surfaces , but that bake alembic to keys is more important