Hi. I do not know what the source of the problem was – but I wiped the sd card and reinstalled max2play and the problem went away.
Not sure worth pursuing, especially noting that gmediarender seems to be gone from v2.29 and you’re recommending using the dlna option in Squeezeserver.
NB, the reason the squeezebox dlna solution isn’t necessarily great is that the UPnP/dlna plugin in Squeezeserver is incompatible with having password security on the server, which you sort of want if you are going to make it accessible through your firewall for remote access.
Thanks for your help anyway.