Flowable-ui text field regex- special characters converted to question mark

**Describe the bug**
I am using flowable/flowable-ui:6.6.0 docker image. created a form, added a text field in that form. I am trying to add this regex [a-zA-Z0-9\(\)\À\Á\Â\Ã\Ä\Å\Ā\Ă\Ą\Ǻ\Æ\Ǽ\Ç\Ć\Ĉ\Ċ\Č\Þ\Ď\Đ\È\É\Ê\Ë\Ē\Ĕ\Ė\Ę\Ě\Ĝ\Ğ\Ġ\Ģ\Ĥ\Ħ\Ì\Í\Î\Ï\Ĩ\Ī\Ĭ\Į\İ\Ĵ\Ķ\Ĺ\Ļ\Ľ\Ŀ\Ł\Ñ\Ń\Ņ\Ň\Ŋ\Ò\Ó\Ô\Õ\Ö\Ø\Ō\Ŏ\Ő\Ǿ\Œ\Ŕ\Ŗ\Ř\Ś\Ŝ\Ş\Š\Ţ\Ť\Ŧ\Ù\Ú\Û\Ü\Ũ\Ū\Ŭ\Ů\Ű\Ų\Ŵ\Ẁ\Ẃ\Ẅ\Ỳ\Ý\Ŷ\Ÿ\Ź\Ż\Ž\+\%\=\*\.\_\s\&\@\£\$\€\¥\#\,\:\;\-]*

to a text field. After saving form and looking back at regex some special characters are converted to question mark ? like below
[a-zA-Z0-9\(\)\À\Á\Â\Ã\Ä\Å\?\?\?\?\Æ\?\Ç\?\?\?\?\Þ\?\?\È\É\Ê\Ë\?\?\?\?\?\\?\?\\?\?\?\?\Ì\Í\Î\Ï\?\?\?\?\?\?\?\?\?\?\?\?\Ñ\?\?\?\?\Ò\Ó\Ô\Õ\Ö\Ø\?\?\?\?\Œ\?\?\?\?\?\?\Š\?\?\?\Ù\Ú\Û\Ü\?\?\?\?\?\?\?\?\?\?\?\Ý\?\Ÿ\?\?\Ž\+\%\=\*\.\_\s\&\@\£\$\€\¥\#\,\:\;\-]*

**Expected behavior**
Supplied special characters in regex shouldn't be converted to ?

**Code**
If applicable, add the code that you are using when having the issue.

**Additional context**

flowable version flowable/flowable-ui:6.6.0