Repairing external insulation patch

Seems to be where they doubled-up the mesh. Wonder did they not bed it in properly and it failed to adhere.

How long is the wall rendered? I'd be thinking that's a warranty job to be honest.

Maybe some PVA on it first then a external filler with that masonary paint of that colour mixed in with it.

It's probably silicon render, k-rend or the like, I wouldn't use PVA on it anyway, especially given that PVA is water based and will reactivate if it gets wet. It's not for use outdoors or in damp areas.

If you could get a small amount of matching k-rend it would be the best bet, but I'm not sure how you would replicate that dashing effect. It might have been a special dashing.

Actually - here's the method for dashing:

https://krend.s3.amazonaws.com/downloads/K-Rend-Application-Instructions_190820_134616.pdf

Try open one and see what you find. If it's anyway workable then you can add a tiny amount of water and try patch that section and see if it sets. I think it goes off in the pack pretty rapidly once it's open though.