The solution is more communication with him. Keep it simple, keep it short, but keep it going regularly. It will help.

If he's actively hostile, that's a different situation entirely. If he is deliberately trying to intimidate you, that's not the same thing at all. Most likely, though, he's not, and simple, professional, friendly communication, on a regular basis, will almost always help.

All human relationships are built on communication. The other two factors, not as important but they do matter, are degree of agreement, and degree of friendliness. Increase those things, even slightly, and the situation will solve itself, eventually or rapidly.

If early communications are met with resistance, that almost doesn't matter. Keep trying. Just make sure they are easy to agree with, and professionally friendly.