I have been in a similar situation, I had a very dear friend, more like a sister really, we flat shared in our teens, so you can imagine we know quite a lot of each other’s secrets!
We both married, had families, and all got on really well, although they moved quite a distance away, we often spent weekends together, and talked a lot on the phone.
I always was aware, that it was probably me doing most of the arranging, but I didn’t mind.
Then a few years ago, I realised she was making excuses for everything I suggested, always some reason why they couldn’t meet up, or I couldn’t go up and visit for the day, as I used to.
Eventually I thought I’d leave it to her, and I haven’t heard a word since!
End of a long friendship, and I don’t know why!