Our glowforge plus keeps dislodging the lens when we try to cut/engrave. We reinstall it and it either gets dislodged and we have to fix it or it falls to the bed. What’s going on? 
Are you talking about the lens inside the printing head?
Yes!
I’ve never had mine to fall out, so I’m not sure how much help I will be, but I’m assuming you are replacing it with the lens tool and you feel it click to the magnet in the head.
@karen2251 I am so sorry the lens dislodged from your Printer Head.
It looks like you sent us an email regarding this issue. I’m going to go ahead and close this forum post and follow up with you there.