Skipping 7th and 15th positions during auto leveling

Hello, Please help to find explanation/fix for the following strange behaviour:
After 3 months normlal usage of the Sovol sv04 printer, auto leveling started to behave strangely. It skips 7th and 15th positions, and reports false (more than 4 mm) height at these locations. Second -not so painful- issue is that the printer drop-pull-drop-pull the Z probe several times at random positions during auto leveling.
You can find related short videos, and the screenshot of 16 leveling positions at this google drive link:
https://drive.google.com/drive/folders/1YErfFRCV3vw_Lb9IIqDk-py5ULSlE2Yd?usp=sharing

Write down all your SV04 user settings (like x-,y- & z-offsets).
Then re-install SV04-firmware, re-run the setup process & check again.