I have an Ender 3 with a 32-bits version 4.2.2 controller board (5 weeks old, <10 prints).
This is a video of what it does during a mesh bed leveling MBL (9 points):
I upgraded the firmware to Marlin 220.127.116.11 to get the MBL feature. Did a few short prints, 1-2 h, and everything was fine. When I was printing a 4 h print, sometime after 2 h I got a huge permanent layer shift in X-axis (5 cm) and it started printing mid-air.
Unaware of all the possibilities I generated the G-code again and checked belt and bolts for loose parts. Started the print again and this time I got the layer shift way sooner, like 30 minutes.
Then I started looking online for other solutions. I swapped stepper motors and again it was the X-axis. Swapped cables and again it was the X-axis. When the stepper was alone at the table with no belt it got the same "holding" that we can see on the video. It does a weird sound like something is holding it. And instead of moving the 10 cm for each point at the MBL it struggles to move 1 cm.
When using the "Move X" it goes smoothly with no problems; 0.1 mm, 1 mm, 10 mm all fine.
I tried to reduce the
DEFAULT_MAX_ACCELERATION to 300 but nothing changed.
I also reinstalled the Creality Ender 3 firmware and the problem persists.
Now when I try to print a simple cube at the middle, it starts printing at the left side and with nasty layer shifts.
What could it be? I am running out of hypothesis to test.