I’m not sure what version you upgraded from or what kind of DHCP server you have in your local network, but this can happen sometimes.
If a device (in this case your cerbo) uses a different dhcp client identifier (this can happen after a software upgrade), some DHCP servers can see that as a new dhcp lease (and thus give out the next available IP address) instead of a renew of the old IP lease.
I have no idea what you’re talking about but it’s not making sense.
Do you mean the link-local IP address? That one is pretty much random.
Last option I can think of would be the Hotspot IP.
You’re posting a screenshot but all the relevant information has been left out.
There is no standard .205 IP address in a GX device and I can’t find any manual that points to such an IP.
Therefor I can only repeat my previous answer: after the upgrade, your local network gave the next available IP address to your Cerbo.
This sometimes happens and it’s not caused by a specific change on Victron’s side.