Well you are not a new account so that eliminates processing a new account.
Since your company sent a physical check rather than an electronic transfer it could be setting in someone’s in-box.
Also any company will withhold crediting your account until the check clears more than two weeks would be excessive.
But you should review your contract to see exactly what the rules are.
But contact them immediately and ask the simple question “Why has my account not been credited with these funds yet?” Be polite and calm.