Such issues are hard to diagnose. Generally speaking:
- No known cases have been caused by Klipper
- Typically, they result from mechanical issues such as:
- Gantry or axes not being square or perpendicular
- Different belt tensions
- Binding axes
- If the printer is losing steps can be checked with the approach detailed in Can I find out whether the printer has lost steps?
- There have also been rare reports with obscure reasons, e.g. this one.