Would you bring it up and ask if you'd done anything 'wrong'?
I have a friend I really care for. Not seen her in person for months because of lockdown. We used to message and email loads, sometimes daily, but over a few weeks now her replies have been a lot slower in coming. I don't know if I'm imagining it or if she is trying to distance herself. And if she is, I don't know why.
Any ideas?