Hi,
thanks
I found the problem. The problem is a Joomla bug, joomla have a script to support html5 on old browsers, this script is located on /media/system/js/html5fallback.js
With this script the integer field not work. Our integer field use the standard of HTML 5, so we will send this report to Joomla developers (in the past we have already helped the team of joomla to fix bugs, and part of our code is included in joomla
)
You can re-create this field with text type, and put in "Format" parameter "Integer" (screenshot 1)