Issue on creating hashtags from tags/categories in Greek language.

[purplecodes]

Issue: When the post tag or category is in Greek language, and the option to Create Hashtags From Tags is selected, it is not displaying properly when the post is shared.
https://vertis.d.pr/pLZZXO

The same issue is happening when choosing the option Create Hashtags From Categories.
If adding a Greek text under the Additional Text area, it is appearing as expected.

[UVLabs]

This issue happens because we're using a method to "clean" the hashtags: https://github.com/Codeinwp/tweet-old-post/blob/master/includes/admin/helpers/class-rop-post-format-helper.php#L572

This method seems to be dropping the greek words because they might not exist here: https://github.com/Codeinwp/tweet-old-post/blob/master/includes/admin/helpers/class-rop-post-format-helper.php#L603

I can't remember why this cleaning method was added but it seems to be the cause, if i output the hashtags before the cleaning happens, it shows the greek hashtags in the array of hashtags.