Unfortunately that didn’t work, but anyway thank you for the suggestion!
Today I coincidentally found a solution (because I never really used the cloze tool). Before I click the text (of course while reviewing) I want to change, I keep the CTRL button pressed. I have to do this anyway for the next shortcut, so I keep it pressed and add the U+B.
Solution: CTRL + Mouse Click + U + B
(This only works with the cloze add on (by default) !!)
→ Edit Field During Review (Cloze) - AnkiWeb