No, the fighter research works. Make sure you are looking in the right area. The research only effects hanger defenses so if you are looking toward your capital ships, they will not be there. It also adds additional fighters per squad, and not additional squads themselves. The quick way to tell how many fighters are in a squad is to mouse over them when you are zoomed out.
Fighter base numbers.
Tec=6 per fighter squad, 5 per bomber squad
Advent=9 per fighter squad, 7 per bomber squad
Vasari=4 per fighter squad, 3 per bomber squad
If the number of fighters in a squad are larger then these then the research is working fine. Also note that for the TEC and the Vasari, 2 levels in the first fighter research are required to gain one fighter, but progresses faster the firther down the research branch. Make sure you pump two levels into the first fighter research to gain any result.
If you still are having problems, please post a reply here and give me the race you are playing and I will look into it further. Thanks.