Defective expansion joint in clinker facade

It is precisely about the execution of expansion joints in general, not about your prefabricated lintels.

By the way, as far as I have read, they do not have to be separated in general, but only in the case of a connection with the inner shell. In your case, this was structurally essential due to the corner window (no support), but it does not always have to be solved that way.

I agree with that.

You seriously haven't realized after six thousand posts that you don't need to write an empty post (and in my opinion, you shouldn't for reasons of netiquette) just to subscribe to the respective thread?????

no....

To turn this "emergency joint" into a virtue, I would consider the possibility of a light strip at this position. This could mask the joint and maybe it will even look better than expected...

considering the possibility of a light strip in this position. That could be used to conceal the joint

Conceal with light? – sounds absurd, but if I think about it carefully: in my youth, there was a detective who did exactly that: nobody would think that a detective sits in a red Ferrari, because when shadowing someone, one wants to be inconspicuous according to the cliché

Hm my first thought was to paint over it with the red tone of the bricks. So of course the stone shape and not the entire joint. But an LED strip over it... could be a solution for concealing it, if it is not regulated (= redone) otherwise.