Remove the onblur code from the fields... That is what is doing the reformatting.
For a true international phone validation, try using:
^\+(?:[0-9] ?){6,14}[0-9]$
I found it here:
https://www.oreilly.com/library/view/regular-expressions-cookbook/9781449327453/ch04s03.html
For more examples google "International phone number regular expression"