MaxChar param on fields doesn't work anymore

If you specify a MaxChar param on a bigtext field the content is cut at the end of the first sentence and not after the number of chars you specified

For a concrete example, use "news" template in the web-templates

The body of the news is called via
<template:field name="newsDesc" maxChar="300"/>
but I have never 300 chars displayed.

I think the problem exists since the taglib has been changed, it used to work a few weeks ago.