I have the web interface configured to bind to a single interface IP addresses which was working in RC1 and in 11.2. I have netwait configured to make sure this interface is up before continuing boot.
On startup there is an error logged (and shows as a notification after) that the web interface can't bind to the address and then it ends up listening on all addresses. If I change the interface after boot then it works as expected.
Due to how 11.3 boots with less visibility I can't see the delay for netwait to know if it is waiting or not but either way it seems the interface tries to bind to the address before it is ready.