I'll throw a bit into this ring. I had a similar situation just last week: I posted by a new girl at the gym that I chatted with a bit, she seemed to hook right away and was staring at me a lot, but said she wasn't single so I backed off (I may be turning to the dark [desperate] side and am going to stop asking about their status). She went off on a stairmaster and I got to watch her rear for the next half hour. I said screw it and found a way to naturally be by her machine as she got off. Looking back, I probably should have gone for an insta-date and close given the good vibe and her availability. Instead, I asked to grab coffee and gave her my number (not sure why I didn't get hers), she seemed pretty onboard for meeting, but over a week later, no contact...
This has been my experience for nearly a year now. I'm realizing my contact count isn't super high due to "building my business and moving out of the house (again)", but of the dozens of cold approaches I've done this year, most went very well and then 0-1 replies to text and 0 dates overall.
I'm trying to tease out the reason for the complete stonewall to even grab coffee with me and my current theory is self-esteem being trashed by my breakup and being denied by 200+ roles in the industry of my degree. Trying to do a lot of inner work, but it does feel nutty each time a new interaction happens and then nothingness. Being 5' 7" and not currently making money, it's quite a fight to not fall into the easy excuse it's due to those things, and stick to focusing on correcting my inner "vibe".
These were all in gyms and either a 2-5 minute chat into grabbing her contact or attempting to "social circle" game over a few interactions.
Thinking back, most of the cold approaches while doing Postmates 6-7 years ago were really short and not much vibe happened. It would be a compliment, names, who are you, what do you do, I gtg, let's meet-up. So it definitely could be that we are going wrong with being great right away but not closing anything physically. I'm actually toying with doing food delivery again just to be out and about when not at the gym or assembling my business.
Edit: reading the "too many good feelings" article does strongly resonate with me, as I am proudly incredibly charismatic and now have crazy stories from world travels and such that tend to come up. Becoming a higher value guy at base seems to have been backfiring when my approach stayed the same.