Friend (23/F) barely acknowledges I (23/M) exist in group settings but can?t stop talking to me over text.

I (23/M) have a friend (23/F) who I have been in the same friend group with for the past couple years, we?ll call her S. We never really used to talk much in the beginning but for the past 3ish months S and I have become much more close, texting every day and hanging out 1 on 1 alot more often. When we do, things seem great and we get along really well, but I?ve noticed when we?re in a group setting she barely acknowledges I exist and I don?t know why.
For example, S?s sister is getting married so she had a wedding social last night that our whole friend group went to. All morning, S and I were texting about general stuff and how excited she was for the social. She left to go help set up around 12, so our conversation ended there. I texted her something around 4, which she didn?t reply to (never did) but I figured she was just busy setting up and didn?t think about it.
We get there and she says Hi and hugs everyone except for me. I tried to talk to her throughout the night but she just brushed me off and was ?too busy? taking care of everything and had no time, but could easily find time to talk to everyone else, dance and have fun. One of my friends who is really good friends with her said I should ask S to dance, and when I said she probably wouldn?t she told me ?you?d be surprised.? I see S passing by on the dance floor and when I ask her all she says is ?No, I can?t? and a walks away. I gave up that point and just enjoyed myself with the rest of my friends. It?s not like it ruined my night or anything but I?m always left confused when it happens.
The above example is a common occurrence that happens when we all hang out as a group. We?re all really close friends so I don?t understand why. S will always go on to text me like normal after, and act like nothing happened. This has happened on multiple occasions, and I don?t know how I should bring it up or if I should just stop talking to her at this point.
As far as I know from what multiple friends told me, S used to have a crush on me when I was in a relationship. My ex and I broke up, and over time I started to develop feelings for S. When I tried to make a move she told me she only saw me as a friend, and I was completely okay with it. From that point on is when we started becoming closer, more so over the past couple months. Our friends joke around about us dating or that we should date, but we always just brush it off.
Recently she has been asking me to do more 1 on 1 stuff with her, like come to the gym with her to show her stuff, teach her how to play guitar, and study together. She has made a bunch of plans for us to do stuff over the summer and has been helping me find a place to live when I have to move our. She?s not a bad friend, but just in a group setting when this happens I?m always left feeling confused and I?m not sure how I should bring it up when she acts like everything is fine after.
TLDR; I talk to friend every day, things are great when we hang out but in a group setting she blows me off and barely talks to me. Unsure what to do.


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