I find that name resolution of local machines in home networks is getting less and less reliable, especially on mobile devices. In an attempt to secure DNS queries, some browsers/devices always use a public DNS server, DNS over HTTPS (DoH), etc. The local DNS server is no longer contacted.
What can be done to get reliable local name resolution - assuming you have an "open", configurable router? Changes on the clients are not feasible, as there are too many different problems in Android/iOS versions and the browsers.