Construction bots tier 3 won't put modules on machines and beacons. Didn't test with tier 4 and nuclear bots
Edit: I've put a buffer chest requesting modules near the machines, and it worked. It's still weird though...
Edit 2: I think i've discovered the issue. When the bug happened, my roboport network was updating, from tier 2 to 3. Now that is updated, is working fine