Maybe he’s feeding his ego if the nature of the contact is flirtatious. I wouldn’t say contacting you once every 1-3 weeks is excessive. It’s probably more the contact. I wouldn’t be happy dating a partner who flirted with other women. I think possibly he was lonely after you separated to different countries. Maybe the contact wasn’t about a desire to rekindle anything but more about feeding his loneliness. If he’s prepared to contact you in a platonic way and you’re happy with that it’s probably okay. If not. Block hit.