Is this an issue from seablock or from construction drones?

What version? The new releases of the mod don't have the drone port

The latest version, that was just installed about 1.5h ago. Thing is, I also can't "place" the drones on the map. I'm running the latest official seablock modpack (zip downloaded from the forums) + a few QOL that should not interfere (bottleneck, LTN, dectorio etc) + construction drones. After building one drone, I can't place it on ground. And yes, the drone port is missing (which is fine, as per your comment).

Thats fine, they work from the inventory now, you just need to have them in your inventory and they will work without a problem