Please help

I can't find Hancock anymore. I did the Silver Shroud quest with him as a companion. After finishing the quest I sent him back to Graygarden (where McCready and Strong already are) but it seems he never managed to get there. I've also experienced the bug where Kent wasn't able to find his way out of the hospital himself but I managed him to go back to Goodneighbour by bumping him to the elevator.

But Hancock's the real problem. The odd thing is, that at Graygarden it says there are 8 people living there. But when I ring the bell to call the settlers only 5 robots + McCready/Strong are there. It seems like Hancock is still alive, otherwise he wouldn't count as a companion. But I can't find him, his nowhere.

Anyone who experienced the same or similar things? Is there a way to bring him back? Maybe ring the bell and wait for 24/48/72 hours?

I don't have a save file before finishing the Silver Shroud quest so it would really pissing me of to have lost my favourite companion...

Wiki says this:

As Hancock somehow seems to be non essential, dismissing him while being far away from a settlement you want him to be(e.g. You're at http://fallout.wikia.com/wiki/Sanctuary_Hills, dismissing him back to http://fallout.wikia.com/wiki/Goodneighbor) will cause him to be killed halfway through his journey way back. He can be killed by anything in the wasteland, even http://fallout.wikia.com/wiki/Mongrel.

Would be really sad if it's that...

Update:

On my oldest save, after finishing the Silver Shroud quest, I've found him in Graygarden!

The odd thing is, it stated that I had 9 settlers there. Even oddlier was when I fast-travelled there, the number immediately went down to 8 with Hancock nowhere to be found. But when I went from the last save (Police Department) there by foot, he was standing right where he always was standing...

Phew... I'm glad... I lost 2 or 3 quests but I'm still glad I haven't lost him forever...

But still, nevertheless, it is a bug.