Younger guys lose interest after I tell them my age

Hi guys, so I don’t really go for younger guys but recently I’m constantly being approached by quite a few. Now I am 29 going on 30 and in all honestly I thought nothing of it. I turn 30 in 2 months and I do look about 26-25 as most people say. You would think that works in my favor right, but wrong. We will have great conversations until I tell these younger men my age. Then they’d get cold feet, limit contact and completely disappear. Why do you think this is happening and how would you suggest I deal with this. 1. Don’t entertain young men 2. Tell them my age very early in conversation 3. Can you give your suggestion, and why do you think this happening

Okay the guys were 22, 24, 25 and 26. I also have no kids and I work as a biologist.