Hey, I’m not sure if the penthouses have alien cores.
You can click P on your penthouse and enter Devices menu, and then search for “Core”.
Then you should be able to tell which type of core it is.
If it’s already an alien core you probably just accidentally pressed Y somewhere
If it isn’t an alien core you can just manually put one in instead of the original… Unless it’s an admin core, then it should have unlimited fuel anyways though.
If you can’t modify it, then it has an admin core. That’s basically an indestructible alien core, so you should have unlimited fuel still.
Are you sure you didn’t accidentally press Y on your base?
If you don’t want to check yourself, you have to go to https://help.hws.global and fill out the template.
There isn’t enough information here for anyone to give anything but guesses.
But if you check what I asked above you might be able to solve it yourself, but you decide if you want to create a new ticket or not.