I'm just going to do a slight recap of my coop experiences and what's going on, just to see if anyone else is experiencing it or how to fix it.
Yesterday: my friend and I were easily able to find each other (almost instantly) anywhere in central yharnam and we beat Father G.
Earlier today: Before the BSB, I was able to use the resonant bell and find games fast and play with randoms and help them out. My friend and I had not done any coop since the night before. This was in the old yharnam area.
Currently: My friend and I both solod the game up to Amelia, and beat her (solo, not coop). Now neither of us can use the beckoning bell anywhere in the entire cathedral area. Since the beckoning bell worked at central yharnam yesterday, we decided to go there. Again though, it was greyed out wherever we went making coop with each other impossible. We both have around 1,000 - 5,000 blood echoes, around 20 insight, and both level 35. We haven't gone anywhere past Amelia except to the fight the two hunters to the left.
Chalice dungeon - I created a chalice, and my friend found it using the glyph code. Our beckoning bell actually worked there, so we decided to try it out. After 5 minutes of searching, we never found each other. We were both in the exact same spot, and we could even see our grey silhouettes standing next to each other.
Tldr; coop is fucked up for my friend and I and its getting pretty frustrating.