Home Assistant OS not detecting update

I am running 2 Home Assistant instances. Both are ESXi VMs, set up with the official ova file. They are on the same network, behind the same firewall.

Every time a update comes out, my 2nd instance detects it fine, but I have to update my main instance using the cli command core update. The utilization of the main instance is arround 5% processor and 20% memory.

This is not a huge hassle, but it would be nice it I can just update from the GUI. Is this fixable?