Happened on my 2014 JK... The part that is still in the rubber boot is somewhat of a button that can be removed... I removed it, cleaned it up and re-soldered it back on.. the temperature your dealing with on a soldering iron is not enough to break the glass as long and you solder it just long enough to make it stick then the portion with the rubber boot just snaps on the “button” to hold it in place. I haven’t has a problem since... And also, I believe Permatex makes a kit to “glue” the button back on. Check out your local auto parts store, they’re usually in the section where they have the rear view mirror glue kits.
Edit... found it on Amazon..
For the record, I'm not sure the glue is vindictive. I mean, it depends on what you may have done to it in the past, I suppose. Did you kill it's family? :)
I think you're looking for conductive glue. Permatex calls it 'rear window tab adhesive', you can get it on amazon or at your local auto parts store. https://www.amazon.com/Permatex-21351-Electrically-Conductive-Defogger/dp/B000HBGKWE
Use conductive adhesive like this to reattach the button to the glass. Be careful lining up the button so the electrical connector can still be plugged in.
Permatex makes a cold solder kit for it. https://www.amazon.com/Permatex-21351-Electrically-Conductive-Defogger/dp/B000HBGKWE
I used this with great success on my 2013 https://smile.amazon.com/gp/product/B000HBGKWE/
OP-
https://www.youtube.com/watch?v=xp-QEdvtC3w&ab_channel=Jsean
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product , if you still have the metal tab -
theres a ton of yt vids if you dont like this one ..
Try automotive window defroster repair glue. At the auto parts store or amazon
Permatex 21351 Electrically Conductive Rear Window Defogger Tab Adhesive https://www.amazon.com/dp/B000HBGKWE/ref=cm_sw_r_cp_apa_pXILAb5YTD5W8
Something like this