ᐅ Efflorescence in the Mortar Joints (New Construction)

Hello, we unfortunately have severe efflorescence in the joints.

Right after the jointing was done, it rained, which caused various substances to settle on the cement mortar like a salt layer (see pictures).

Does anyone know if the joints will eventually "wash out" due to weathering, or is this more likely a defect that means we should ask the builder to fix it?

Thanks for your answers