[Bug]: Not possible to input negative values (minus sign) in calibration line

[marcelhoogantink]

What happened?

Trying to input a negative value on a power calibration line, it was not possible to enter a negative value (minus sign with keyboard), while using the up-down-array on th right side of the input field, does allow neative values when clicking on the down arrow.

(entering a number first and then go to the left using the arrow-keys on the keyboard, and then put a minus sign in front of it, did work though)

What browsers are you seeing the problem on?

Chrome and others

Relevant stacktrace