Cleaning damages Please share experiences

Requesting experience reports or help.
Timber frame construction
Plastered with synthetic resin plaster
Spalling only at the areas above these windows on the weather side.
No other areas
Age of the house 4 years.
Undercoat or base coat ok
Only the top coat affected.
Now concerning warranty claims because the expert report by the paint manufacturer states external impact, e.g. hail.

What does your building surveyor say?

I don't have one (yet), as I would have to pay in advance for it. I just wanted to get a feel for things here first...

Well, then it's expert report against expert report. But if it only concerns the weather page, you probably won’t have many chances there.

I suspect damage from the inside here, something with the roller shutter box where moisture urgently needs to be directed outside under the plaster.