I have a BLTouch on my 3 i3 2020s and have suspected they weren't working properly for some time, but yesterday I confirmed it.
Running RC7, I've enabled the BLTouch and set things up according to the docs. The system goes through the grid and then starts to print but I've noticed if my bed isn't perfect to start, the first layer comes out crooked anyway. I've always leveled my beds to start just to keep things simple. Yesterday I noticed the print was too high on the front left and perfect back right so I spun the hold-down a bit and restarted, the front left was then too close even after another autolevel.
I also switch out beds, one had PEI, one has Printbite and another is just glass, and I have to change the offset each time. Shouldn't it compensate automagically?
I run Simplify3D and am thinking it may have something to do with my script unless I just missed something in the firmware...
Here's my start script from S3D, it differs slightly (temps/speed) for different materials but gives the gist of it. I can post the configuration.h if nothing here looks suspect.
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M104 S235 ;Set Hotend to 238
G1 F3000 ;Slow Down for IGUS X
G28 ; home all axes
G29 ; Autolevel
G1 X5 Y5 Z10 F3600 ; Move to position
M109 S238 ; set hotend to temp and wait
G92 E0 ; zero the extruded length
G1 F200 E10 ; extrude 10mm of feed stock
G92 E0 ; zero the extruded length again
G1 F3000 ; set speed to 120mm/s
;Put printing message on LCD screen
M117 The Cake is a Lie!