I had some suspect about a bug. I observed another strange flavour using the tab filter bar:

a) if i select the filter tab 'Change' (only change template) the overview screen seem working well : i can select a template in a diffrent window and i can delete it (I have the confirmation pop-up)

b) if I select the workorder filter tab (only Workorder template) I ahve the same flavour as previously depicted and I can't delete the template.

Answering your question:

I go into the overview screen, I select a template and I fall into the edit screen into a different window, here I can modify some attributes but I can also to cancel modification and come back into the previous screen (Template overview) otherwise why I have a ref with cancel/close window option ?