I cannot find Preston. I currently have a side quest where I have to report my progress (on Taking Poing: Hangman's Alley) to Preston.

The last time I saw him was when I went to The Castle (in Taking Independence).

I killed the Queen, and there was a bit of a glitch where it said to kill the remaining egg clutches, and to talk to the Minutemen in the courtyard.

Finally, I went to Sanctuary Hills, and got the progress on those 2 parts of the quest.

But, Preston is gone. I did read somewhere about a problem with him on this quest... but, since then, I have done several other missions.

I have an older save point that is mid battle in the Castle (before killing the queen)... but when I loaded that game, he was already missing.

The only other save I have is before I even made my way to the Castle... so there is a half hour of travel/fighting my way there... as well as lost progress on the other mission I ran afterwards.

I don't want to repeat all the other stuff I have done. Is there any way to find him? fix this bug? work around it?