I searched and searched for a replacement too. In the last year I found raindrop.io, and I'm really happy with it. (No affiliation)
I tried pinboard but it wasn't very stable and full-text search didn't work for me on multiple sites (he was great about refunding me, though!). After that I researched all options I could find and raindop truly works just how I wanted on all my devices. The only time I had a minor issue with them was near the start and they fixed it in a few days.