Single and sad about couple friends

I'm a newly single female 60-something after ending a 14-year relationship (overdue and happily). I stayed too long for fear of being alone. Now that I am alone, I'm relearning what I seemed to do so effortlessly in my youth--be fulfilled and energized as a singleton. For the most part, I'm managing well. But I'm sad about how long-time friends who are cis-het couples and a similar age are pulling away. These couples have seen me through a lot and know me well. Now that I'm no longer partnered, though, I feel almost as if I have some disease they can see and I can't. I reach out to invite them to things and am ignored. Or only the woman in the couple will show up for a coffee (I've never had any issues with their partners). Through other friends, I know they are socially active and I get bits of news ("at brunch the other day..." or "when we went to this concert..."). More than my relationship ending (on my terms and for the right reasons), this really cuts deep. I haven't shed a tear about my former partner. But I am gutted by how the attitude of my friends seems to rest on my status as in or out of a couple. Yes, I need new friends! Working on it... But have others had this experience? How do you understand it?