Problem with attaching Blueprint actors

I am trying to add a Blueprint component to a spaceship character (IE cannons that you can “cast” stuff to, to activate a “fire” function).
Each time I do this, weather manually in the Editor or at runtime (AttachToComponent node), my character has weird sideway movements and doesn’t move correctly. Like, I move forwards and also move a little sideways, or try to go backwards but instead go diagonally…
This is the second time this is affecting me. It can’t be my BP code, since it happened to me in a completely different project, and it turned out to be an extra actor to a “rifle” BP actor that the player was carrying. Deleting it solved the problem
I can upload the whole project online if you want?
Pleeeeeease help me! This is really frustrating! No one has the same problem online!
Thank you,
PS: I’m an “intermediate-newbie”, got the main concepts and ideas, but stuff missing. Using UE4.23.