sounds to me yoour wrapping the wrong direction with the ptfe tape and its unwinding in the socket!
i use 14-18 wraps around normally keeping it reasonably tight wound then running my fingers over it to bite the thread profile. You want the fitting to start tightening when half way in the socket + a good umphf at the end the reason being when we fit these we fit them once!
personally i dont use loctite- i use liquid ptfe, i use to have tru-blu but found it was expensive stained everything blue and stayed on your skin for three days
now i use T plus 2, this stuff will seal the hole in the Titanic and just wipes of shin and fabric etc, one of the best things in my toolbox
https://www.ebay.co.uk/itm/Todays-Tools ... SwX1la5Far