I have the same issue with the same Panasonic and purchased a $25 decent universal remote and the "ok" is the same as the menu button so it's useless for this issue after reading came to find only the expensive harmony remotes have the capability of doing what is necessary. At that rate this TV is going in the trash.
Solandri :
Buy a universal remote. They're about $10-$20 on Amazon. Or if your smartphone has an IR blaster, use a universal remote app on your phone.