Hi @anon75630733 and welcome to the forum!
This is a known issue… you’ll find quite a long trail of discussion about here: Project Template assigned tasks show up in My Tasks automatically
(and the moderators might merge your post with that thread).
While there’s no true solution for it at present, there are several workarounds to choose from which you can find discussed here: 🔥 Hottest feature requests and their workarounds - see item F4.