Yeah those issues can be really frustrating. I find textured PEI sheets to be the easiest to get working, if adhesion suddenly stops being good, I first try washing with soap and water, then I try adjusting the z-offset, then drying the filament and playing with bed temperatures, curling can happen in both cases of if the temperature is too low and too high. Additionally, with corners lifting on certain prints, you might just need a brim.

I had a BLTouch for a few months, but I found it to be way more trouble than it was worth (probably mostly due to its temperature sensitivity and the heated enclosure). I ended up switching over to a Klackender probe, which has been more reliable to me.