Start, Restart and Stop are all dimmed after port change

After a change of port in ports.conf, from:

Listen 80

to:

Listen 8080

the Start, Restart and Stop menu alternatives are all dimmed.
The webb works, http://localhost:8080 is OK, i.e. Apache is running and the site is running on the new port.

Maybe the menu disappeared after the first restart made after the port change.

The log also said (although I do not think it is directly related):
apr_sockadr_info_get() failed for myServerName
Could not reliably determine the server's fully qualified domain name, using 127.0.0.1 for ServerName