Still nothing.
I needed to get some development work done, so tried the docker reset:
Docker > preferences > reset to factory defaults.
After this the containers were rebuilt and they started correctly. The ports are still assigned to slirp but the containers are working correctly.
steve@Dibbler:~/dev/sites/docker/newgt$ sudo lsof -i -n -P | grep TCP|grep dock
com.docke 46505 steve 11u IPv4 0xd0e643bff97a8563 0t0 TCP *:9013 (LISTEN)
com.docke 46505 steve 13u IPv6 0xd0e643bfff718173 0t0 TCP [::1]:9013 (LISTEN)
com.docke 46505 steve 14u IPv4 0xd0e643bfede75183 0t0 TCP *:8013 (LISTEN)
com.docke 46505 steve 15u IPv6 0xd0e643bfe4d3fbf3 0t0 TCP [::1]:8013 (LISTEN)
steve@Dibbler:~/dev/sites/docker/newgt$ ps aux | grep 46505
steve 48086 0.0 0.0 2445080 832 s001 S+ 8:56AM 0:00.00 grep 46505
steve 46505 0.0 0.0 2573644 3256 ?? Ss 8:40AM 0:21.81 com.docker.slirp --db /Users/steve/Library/Containers/com.docker.docker/Data/s40 --socket fd:3 --port-control fd:4 --vsock-path /Users/steve/Library/Containers/com.docker.docker/Data/@connect
steve@Dibbler:~/dev/sites/docker/newgt$
I suspect that this is a duplicate of: