I'm running the bed that came with my Ender 3 pro (using a pei sheet, this is repeatable with glass too), been having this issue for a while I think. Is it time to replace the bed? Update: Figured it out, what my bl touch was attached to was very loose, and was going up on the far side of the x gantry. and it's now fine.

I bought a smart filament runout sensor a month ago, and I've been having problems off and on with it. Right now I have it mounted just outside of the extruder of my ender 3 and it keeps triggering on longer prints. So my question for you guys is how do you have yours mounted and what's your runout length? Thanks in advance.