Hi,
I have a SMA Sunny Webbox that I can access from my local network using http://192.168.200.xxx
It’s also been configured to update the SMA Sunny Portal.
Both methods work fine.
I’ve tried the SMA Solar integration and I have the same issue as the OP.
I’m running Home Assistant 2022.4.6 on a RPi 3B.
It’s on a reserved IP address and can talk to my Tasmota devices and has internet access.