Your bank probably will not accept the check because it's not payable to you. It's payable to the new institution. "FBO" identifies you as the owner of the 401(k), not as a payee. This is a direct trustee-to-trustee transfer, not an indirect rollover. The paper passes through your hands, but the money doesn't pass through your hands. All you can do with the check is send it to the new institution. You're just a messenger.
