Minimserver keeps 'disappearing'

[simoncn]

IGMP snooping should be disabled unless you have a degree in network engineering and know how it should be configured to work reliably.

UPnP (internal) should be enabled. Often this is just about the router itself being visible using UPnP but it does no harm and might help in some cases.

These problems can be very difficult to solve. Debugging by substitution will get you there in the end but may require spending money on the substitute equipment.

The problems usually involve routers and wireless or powerline connections. Switches and wired Ethernet connections normally work OK.