Why does <pe:keyFilter /> and <p:keyFilter /> behave diversely in different browsers?

Question

I have the following code to restrict an input field to numbers only:

<p:inputText value="#{myBean.tlf}" maxlength="9">
    <pe:keyFilter regEx="/[\d\-\.]/" />
    <p:ajax />
</p:inputText>

It is working like I expect in Firefox but not in Chrome or IE/Edge, where it allows someone to write values that are in number keys but aren't numbers like @|~ and so on.

Testable on PrimeFaces Showcase for <p:keyFilter /> also.

What is the reason? Is it possibly a bug in PrimeFaces (Extensions)?

EDIT: I'm using PF 5.3, Chrome 50, Edge 20 and IE 11.