SpellCheck & TrackChanges: corrected errors still marked

problem:

(with SpellCheck AND TrackChanges activated type something into a word that creates a SpellCheck-error. It gets marked correctly. Delete what you typed (so that the word is correct again) => the SpellCheck-error is still shown.

to reproduce:

• open current task "Locworld presentation visualReview" on https://test.translate5.net/
• open segment Nr. 8 "What is Free Software"
• Add an "s" at the end of "Software"
• The word is now marked as a spell error
• Remove the "s" again
• The word remains marked