They might have put the wrong one in - it does happen!My PV is split between 2 same size arrays, east and west. The max output should be 6.7kW but now we’re getting a lot more sun, I’ve realised it’s clipping at 3.8kW. Even today with the sun directly overhead and a clear sky, it’s maxed out at 3.8kW.
I have a 5kW inverter so would expect to see close to that, certainly over the 3.8kW.
I have emailed the installer and will follow up with a call on Monday but what is likely to be the problem? Is it possibly an inverter configuration issue?