Tube anemone disappeared?

[Jennduhh]

Hey all,
Back again with another situation.
I have a tube anemone that I've had for a few weeks now.
2 days ago, it decided it wanted to move & got caught in the powerhead. Luckily, I caught it right away (I was about to leave for work, so could've been way worse).
I tucked it back in the sand bed & turned the powerhead off, since I knew it would be most likely moving again.
Came home from work & it had found a new spot in a hole in a rock, was completely opened & seemed happy. It's tube was still intact, but it did have damage to the end if about 3 tentacles.
I plugged the powerhead back in, checked on it a few times over the following few hours & all was good.
Fast forward to today. When I left for work it was in the same spot it had been in on the rock, but I came home from work & it's gone. Like, entirely. The outer tube is in the rock, so im guessing it dropped it & moved because of the damage it took, but I cannot find it ANYWHERE in the tank. I didnt dig thru the sand bed or anything but it's about 1.5" in diameter so I figure it'd be fairly easy to see, no matter where it went.
I took the powerhead out & checked it, it didn't get caught in there that I found, unless it somehow chopped it into tiny bits. It's not in any of my filtration.
Where else could it be? How long do they hide in the sand bed as they rebuild their tube? Do they come out at all as they rebuild their tube?
If it somehow died, should I search for it to remove it? Would it be obvious that it had died & laying in the tank somewhere?

 

[Jennduhh]

Update:
I just found this. Does that mean it died? Or does that just happen when it sheds it tube?

 

[VintageReefer]

I don’t know what that is but have you found any of the feelers? Tube anemone are usually orange or purple so if it was chopped up you’d probably find them all over.

It can take several days to a week to rebuild a tube. They don’t come out when they rebuild it. They secrete a substance that mixes with sand and forms a new tube

 

[Jennduhh]

I don’t know what that is but have you found any of the feelers? Tube anemone are usually orange or purple so if it was chopped up you’d probably find them all over.

It can take several days to a week to rebuild a tube. They don’t come out when they rebuild it. They secrete a substance that mixes with sand and forms a new tube

I haven't found any of its tentacles/feelers. It was a "green laser ghost" tube, so they'd be a bit harder to see, but still visible in my mind.
This was it's sale picture.

 

[VintageReefer]

Pretty sure they can also shed their crown, meaning the section with the tentacles / feelers detached from the worm. This can regrow

Regardless, if you aren’t finding that crown piece or a worm then I would assume it’s alive and underground.

I had one but it was a long time ago. Just throwing out things I remember

 

[VintageReefer]

Did you ever find the tube anemone?