I have probably found the cause/solution
On some IPFire devices, there may be a problem with the command
wioscan -s red0
Below are the results from a test IPFire on VM
Below are the results from the problematic IPFire device
Multiple IP addresses assigned to one MAC address.
It seems that with so many addresses, the wioscan -s red0
command does not terminate (hangs).
I am not a programmer 
, and to get around the problem,
I commented out three lines:
#if ( $netsettings{'RED_TYPE'} eq 'STATIC' || $netsettings{'RED_TYPE'} eq 'DHCP' ) {
# push (@ifaces, "RED");
#}
in the file:
/var/ipfire/wio/wio.pl
The author(s) of the script and people more experienced in IPFire programming, I would like to ask for analysis, checking and possible correction.
Best regards
Tom