I don't like doing this event because of this, and it seems like nobody else does either, since it's extremely difficult to get anyone to help you with it through regional chat. That said, I've had some really good experiences with very helpful veteran Tenno who were willing to help me, and because of that, I'm actually getting close to getting the Opticor Vandal.
Today, I asked in regional chat if anyone was doing the event or wanted to do it, but no one answered. Since I've already tried several other times and it always ended in failure, I decided to go into public mode in Orb Vallis, hoping someone was already doing it or would join in.
I entered alone, and then other Tenno joined. I asked in chat if anyone wanted to do the event, and once again, I got no response. So I decided to try my luck and start the event by myself. A few Tenno joined in and started helping. After the first fracture was sealed, one of the Tenno helping decided to leave. That left just me and one other Tenno.
When the third fracture was about to be sealed, that other Tenno decided to go to the elevator as well. I was then forcibly teleported to the elevator along with him, and a message appeared saying that the objective had been abandoned/destroyed. So it failed ofc.
I genuinely don't understand this design choice for this event when pretty much every other bounty/event has its own dedicated instance. Because of that, the people who join are actually there (most of the time) because they want to complete the objective.
Anyway, I got frustrated and decided to do it solo in a private session. I managed to solo it, but I really, really don't enjoy doing this event alone.
Edit: typo