It's not bug.
If you explore research.xml in assets folder, You will know that Producing the marauder intercepter is unlocked by completing the reseach of carrier Hull.
It's somewhat complicated.
You should get the Items of Carrier Hull, & should complete the Researches of Alien reactor, Researches of Cruiser Hull for Starting the reseach of Carrier Hull.
Items of Carrier Hull is gained by producing Disassembling Carrier Datacore in part of Aircraft manufacture.
1. research alien reactor.
2. Get cruiser datacore.
3. research disassembling cruiser datacore.
4. Get another one of cruiser datacore
5. Produce Cruiser datacore Disassembly --> 1 item Cruiser Hull produced.
6. can start & complete research of Cruiser Hull.
7. Get one Carrier datacore.
8. research of Carrier datacore disassembly.
9. get another one of carrier datacore.
10. produce carrier datacore dissassembly. --> 1 item Carrier Hull produced.
11. can start & complete research of Carrier Hull.
12. after all of above, manufacture of Marauder intercepor will be appeared.
Good luck.
This Xenophobia mod is very exciting but, a little difficult.