Came across this – from the read of it, seems only applicable to residence cards of family members of EU citizens. Or is it also applicable to normal residence cards “Titre de sejour” of all third country nationals ?
[https://www.luxtimes.lu/luxembourg/government-to-finalise-switch-to-new-residence-permits/1620858.html](https://www.luxtimes.lu/luxembourg/government-to-finalise-switch-to-new-residence-permits/1620858.html)