On my DIY Hypercube Evolution I have replaced plain aluminum heated bed with magnetic one for removing large prints off of it easier (blue tape makes it near impossible to remove them without damaging the print or bed surface). Thus I ended up replacing inductive probe with BLTouch clone (3DTouch). The printer is driven by MKS GenL v2 (pretty good for 8bit board) and Marlin 188.8.131.52.
After I replace bed and probe I of course went to level everything (UBL 10x10) and found this weird pattern on my leveling. Below are two examples 1st one is with Z homing at 0,0 and second one with Z homing at center of bed (x_max/2,y_max/2). There were no change in configuration between those two samples. When re-run it with cold bed everything looks absolutely normal. Enabling options to pause heating while probing does not change the result (and I can see by LEDs next to MOSFETs that heating is disabled when probing).
I would like to ask community here whether this is a known hardware issue or a bug in Marlin somehow?
Z_SAFE_HOMING disabled, bed heated to 60 °C
Z_SAFE_HOMING enabled, bed heated to 60 °C
Note, running 3DTouch on cold bed has been very very stable and consistent and repeatability test (cold AND hot) gets me around 0.03 mm deviation.