Possible encoding issue in version DHTMLX Suite 5.1.0

I am sending a text update of a cell using the dataprocessor. The dataprocessor is set to send UTF-8.

The received string from JSON is:
“Ã¥tgärder RÄKSMÖRGÃ…S åäö é üû”
and should translate to
“åtgärder RÄKSMÖRGÅS åäö”.

However, only lower case åäö translates - the resulting string is “åtgärder R� KSM� RG� S åäö é üû”.
Upper case characters “Å”, “Ä”, and “Ö” are not translated correct when converting from UTF-8 to ISO-8859-1.

To my understanding, the characters “Å”, “Ä” and “Ö” (Swedish vowels) are not properly encoded to UTF-8 prior to sending the JSON.
I suspect the characters are incorrectly encoded in the dataprocessor, since all other text translates correct.

My Java code for encoding from UTF-8 to ISO-8859-1:
byte[] test = new String(iso88591, “UTF-8”).getBytes(“ISO-8859-1”);
String newString = new String(test, “ISO-8859-1”);

Can you please confirm if this is a bug or not?

When entering ampersand sign “&” into an editable cell the value saves correctly and displays correctly until the
next edit. In edit mode the cell shows “&” instead of “&”.

I guess this is a bug too.