Found this support article.
https://support.ultimaker.com/hc/en-us/articles/360011576000-ER45-Capacitive-sensor-low-performance-or-interference-detected
If the printer reports "interference on the signal" consistently and you encounter frequent issues with active leveling, please contact support.
If you require further support, please contact us by submitting a ticket.
Please ensure to include the error number (ERXX) and your printer's log files.