Your regex is technically incorrect. You can't have a + after a {,} qualifier, it's like saying .*+ or .?* (the + is a special metacharacter in regex meaning "one or more", just like * means "zero or more").
Try
^[-+]?[0-9]{1,3}(\.[0-9]{1,2})$Notice the {1,3}+ is just a {1,3}.