LibreELEC-livingroom:~ # connmanctl config wlan0 ipv6 manual 2001:470:e1e0:9::25
0 64 2001:470:e9::1
Error wlan0: Method "SetProperty" with signature "sv" on interface "net.connman.Service" doesn't exist

LibreELEC-livingroom:~ # connmanctl config wlan0_dca632afc3f1_cable ipv6 manual
2001:470:e1e0:9::250 64 2001:470:e9::1
Error wlan0_dca632afc3f1_cable: Method "SetProperty" with signature "sv" on interface "net.connman.Service" doesn't exist