PbS bonding ....
The bonds in PbS are predominantly covalent.
Lead(II) sulfide is a network solid with a high melting point. That doesn't make it "ionic", nor does the fact that it is a metal bonded to nonmetal. That doesn't make it "ionic." The percent ionic character of the bonds between lead and sulfur is 1.6% (or about 98.4% covalent).
% ionic character = 100(1 - e^(-ΔEN²/4))
Therefore, the bonding in lead(II) sulfide is highly covalent. The same is true of lead(IV) sulfide. Please don't confuse the oxidation states of lead in PbS and PbS2 with actual ionic charges. (The oxidation state is the hypothetical ionic charge if all the bonds are 100% ionic. Of course, we know that there are no 100% ionic bonds.) Lead(IV) compounds appear to be more "covalent" because the structure of the substance is more molecular, and less like a network of atoms alternating throughout the sample. For many metals with multiple oxidation states, the higher the oxidation state, the more "covalent" the bonds.