HTML filtering removes dash from data-* attributes for non Super Users with J3.8.8

Hi, several of my clients are using JoomUnited extensions like DropFiles in their FlexiContent articles. This puts a HTML snippet into the editor which contains data attributes. When saving the article, these attributes get corrupted, which does not happen with a super user account. This is what happens - to me it looks like a "misbehaving" input filter: 

before saving / after saving with a super user account: 
data-dropfilescategory="63" data-category="63"

after saving with an administrator account: 
datadropfilescategory="63" datacategory="63"

As a mesurement, I tried with TinyMCE instead of JCE Editor, but I get the same result. The developers of JoomUnited claim that it's flexiContent, and it seems to be so as I have only complaints from clients using this combination of extensions.

I use the latest versions of joomla and flexiContent, in fact, I think it happened with the latest update.

Hello

you do not mention what kind of validation are doing for the description field
there is configuration for server-side validation

the default is Joomla text filters

Hello

ok i remember now this issue , reading about it a month ago

if you have J3.8.8 (aka the latest for today 22-June 2018)
Then it is a bug of J3.8.8

since if you are using the Default BlackList  filtering (or some Blacklist filtering)
then it will occur
github.com/joomla/joomla-cms/issues/20579

About only issue happens with Flexicontent is false in this case
funny thing, i think they did not spent time to test

Please pass information to Joomunited so that they can read about it
it was reported a full month ago !  so i do not know how they relate this to flexicontent

Hello

you will have the fix when you install J3.8.9 (when it gets released)

Hello

but you can apply fix of J3.8.9 now  ...
github.com/joomla/joomla-cms/commit/66de...be6de1a4ab30d4c1R867