Unable to ping OMV from a different VLAN

Hello, I recently did a fresh install of OMV6 after using OMV5 for a while without problems. OMV is on my default untagged network (192.168.0.20), and I have a machine on a separate VLAN (192.168.20.40).

ping results:

OMV to machine on same network: OK

OMV to machine on VLAN20: unreachable

VLAN20 to OMV: unreachable

VLAN20 to another machine on default network: OK

I have deleted all the firewall rules on my router so I believe this problem is specific to OMV and not the network. Is there some additional setting I need to mess around with in OMV6 to fix this?

My router/firewall (Unifi) automatically created firewall rules that allow communication across VLANs. That is how I can ping from VLAN20 to a different device (let's call it DeviceX) on my default network (same network that OMV is on). When I create a firewall rule to restrict the VLAN, it can no longer ping DeviceX (as expected), so I believe my network is set up correctly.

However, for some reason OMV is not accessible to VLAN20 even when all my "Block" firewall rules are disabled and communication across VLANs are allowed. This is why I am asking if there's something specific to OMV6 that could be causing this, as it's the only machine that I can't ping.