Configure DHCP client on bridge (instead of 60G interface).
When individual ports are made members of bridge (in your case 60G wifi and ether ports), they are then "slaves" and L3 config on them is not valid ... DHCP client is such L3 setting. So from the moment port is made member of a bridge, all L3 config should go to bridge interface.
And yes, QuickSet is known to create invalid config sometimes. And is known to break config made in "Advanced" part of WebFig or Winbox. So it's best to avoid using QuickSet after initial configuration is done.
The Quickset has ( on v6 ) several choices.
When you open one, you open the chosen template, which has nothing to do with the pre-existing configuration.
Probably It Is this that you experienced.
I didn’t open any template…as I logged in first time I arrived at the quickset page and was expecting that when CPE (template) was indicated that this was the configuration.
Yep, likely the CPE is the "default" template (or first template in the list) and it auto-opens when you select Quickset, you can change it (top left), still it has nothing to do with current configuration, it represents a (poorly made) "helper" to create a configuration, but it only works properly IF it is used only once and from a reset device, as it assumes a number of settings that may have been changed and the results of applying the template might be way off.