According to your regular expression you cannot have white spaces in the text.
You gave the address: 24 Tamboti Road as an example, which isn't valid. My guess is that: " 24TambotiRoad" will pass your validation. Apparently the validator widget ignores whitespaces.
It really depends on how strict you want to validate, I would recommend taking a look at the site https://regex101.com/ this allows you to test some regular expressions and you'll see that your expression only matches the first part of the address. Due to the whitespace the word "Road" doesn't match the expression.
You could for example use: (\d+)(\s)(\D+) which says: Multiple digits followed by 1 whitespace character, followed by multiple non-Digits. However this wouldn't allow you to use numbers but does allow for special characters.
I still think there is a bug in Mendix. When the string is 12 the regex '^[0-0]' will fail. To my opinion Mendix falsly rejects it because the string is more then one character. Any regex tester I tried gives a match, but only Mendix will reject it....
There was a typo in the regex should have been^ [0-9]. But when I enter this and enter the string 12 it will give a match.