Election of medical coverage w j2

if j1 and j2 both have same medical coverage will that be an issue if I sign up for both?

Q2: will it be suspect if I go the route of declining coverage at j2? any personal anecdotes or insight would be GREATLY appreciated

Also is it worrisome if I decide to decline but then jeopardize my standing at j1 lose it and now I have no med coverage? (Technically only until next enrollment right?)