Nice to see you back. But, sorry to hear all the hogs have gone awol. I won’t repeat all the usual potential reasons because I know you know them all.
That’s the problem with hogs, there’s so much of their day to day lives that we can’t know about, so there’s always something to worry about with them. All you can do is hope that at least some of them return. Hopefully some with some hoglets in tow. (the females here often used to be away for a couple of weeks at hoglet time).
I do feel for you. It’s worrying enough when one disappears, let alone all of them. Fingers crossed for some better news soon.