How long ago was All Might's first fight against AFO? Not the second one that got the villain into Tartarus.
That one basically crippled him and he went on doing hero work even though he could only maintain his super-body-form for like 5 minutes, yet no one noticed for quite a while.

I'd say that after that, All Might couldn't possibly wield the power of OFA in any reasonable manner and thus nothing manifested.
But he recieved the power as a teenager, so I'm not sure how long it took for him to take down AFOs syndicate..