@Britgirl I’m using 9.1.4 on the clients (Linux Mint and Windows 11) and the host (Windows 11 Pro). I also had the same problem on a Windows 10 host running 9.1.x.
I’m not relying on the host advertising on the network – I’ve got it set up as a specific connection.
I’ve put the server log into debug mode but sometimes it can go for a week or more without glitching.