Tabstop - Delta contains unexpected byte sequence

[voodoohoo]

If Tabstops are defined, e.g. left Tabstop on Position 100, typing a single Tab leads to this delta

[{"attributes":{"tab":"1"},"insert":""},{"attributes":{"line-part":true},"insert":""},{"attributes":{"tabs-cont":"TABS-CONT"},"insert":"\n"}]
All of the insert operations for the attributes tab and line-part contains a byte sequence of EF BB BF

I think that is bug within the tabstop logic. I've noticed that while writing a Delta2Rtf converter which leads to unexpected results when using defined tabstops

[voodoohoo]

Workaround is to remove all non ASCII Character (beware of special characters like german umlauts) after rte.getValue()

delta = delta.replaceAll("[^\\x00-\\x7F]", "");