A couple of things I should have mentioned. When the
oil pan is off and clean, check that it is straight and not distorted around the holes from previous over tightening of the bolts. If is is not straight, use a pair of channel lock pliers and straighten it. Use a hammer to flatten around and holes if needed.
Once the pan is on and the sealant is cured, check the bolt tightness and snug up any that need it. The gasket will compress a little when clamped up.