Welcome to the forum !
Now, I've had a case of this also like you in a new-born calf which was due to a dislocation of it's jaw sustained during calving, now I'm not saying this is what's happened with your calf but it's one possibility and would explain why it is not suckling. [You may want to consider tubing it so that it gets that all important first colostrum]
Meanwhile check it's jaw, jaw muscles and tendons in that area, if you are not sure then try your vet.
Let us know how you do please ?