Printable View
Have BLTouch3.1 on an Ender3 pro with an skr mini 1.2 and newest marlin. Works fine if I manually level bed from the panel. If I run the G29 command however, it will only touch down on anywhere from 1 to 3 grid points then stop as if it completed the entire grid, starts printing after that. I have Bilinear with a 3x3 grid setup.
Mine did the same after about 6 months. I have seen reports of others with the same issue, and generally a replacement solves the issue, suggesting that it is the sensor that is at fault. I decided I didn't want to deal with that issue anymore, so I got a spring steel bed surface and an inductive sensor. I am personally much happier with this. I now have my Ender 3 Pro set up with Micro Swiss direct drive kit, spring steel sheet, inductive probe, and the yellow springs, and SKR mini E3 1.2, all running on Marlin 2.0.5.4. I have the inductive sensor connected to the servo port on the board, which means I still have the OE endstop working as well. Auto home will trip the original endstop, bed level will use the sensor, and if the sensor ever fails, the endstop will trigger preventing a bed crash. I like to use a 5x5 grid, myself.
In short, your options are to replace your BLTouch with another sensor, be it BLTouch, clone, inductive, capacitive, or ir sensor, or to get rid of the sensor entirely and go back to manual leveling or manual mesh leveling.