I had to change the code slightly to test that but the entity/ grenade creation seems to work flawlessly when ent_create is triggered on the client's computer/ application. This can be used as a workaround but for multiple reasons I would prefer to keep the grenade creation server-side.

(EDIT: In the old/ regular version ent_create only gets called on the server(-client), and all player and bot entities request the creation by some skill manipulation.)