The new version of Debian 9.5 stops working connmanctl.

I downloaded the new version of Debian 9.5 2018-10-07 4GB SD LXQT.
BBBV
When setting up a Wi-Fi network, wireless Internet is no longer configured.
debian @ beaglebone: ~ $ sudo connmanctl

tether wifi disable
enable wifi
scan wifi
services
agent on
connect wifi _ ***********

gives an error message.

On version 9.4, everything worked fine.

I downloaded the new version of Debian 9.5 2018-10-07 4GB SD LXQT.
BBBV

Do you mean BeagleBone Black Wireless?

When setting up a Wi-Fi network, wireless Internet is no longer configured.
debian @ beaglebone: ~ $ sudo connmanctl

tether wifi disable

This likely give a harmless error.

enable wifi

Probably also issues a harmless warning.

scan wifi
services
agent on
connect wifi _ ***********

What did you actually fill in here? This has to be one of the listed services.

gives an error message.

Please share the error message.