Update: I have two almost identical configurations of this that are working.
On the original Docker machine / VirtualBox system I had three websites each running with the same configuration - a docker-compose file with NGINX, PHP and MYSQL containers. Three folders, each with docker-compose.yml and linked Dockerfiles. The only difference is the database and some of the source files and images.
After the migration to the 1.11.1 beta, two are working and one (see above) is not. If I switch mack to virtual box all three are working.
Where should I now look to try to determine the difference?
Steve