Excel not asking to save a template, it just overwrites it

We use a number of different Excel templates at my organisation, they are all XLTM format.
The normal behavior is to open one of these templates, make changes to it and hit save. When you hit save, it opens the save as dialog and you enter a file name and it will save it in XLSM format.
On my computer though, when i open one of these templates and hit save, it just overwrites the template and it doesn't display the Save As dialog.
This happens when hitting Ctrl + S, clicking the save icon and when exiting the program. When you exit, it does ask you if you want to save but hitting save just overwrites it.

I've tried reinstalling but it didn't help.

Any suggestions?
Thanks

Hi,
How do you open your *.xlmt file? Open empty excel and then File - Open? Or double-click on *.xlmt file?
There is difference because you can open your template with purpuse to correct it OR you can open copy of this template.
Right-click on your file and try to choose "New" - this should open copy of template and then you will try to save - SaveAs dialog should appear. If you choose "Open" - this wil open current template and when you will save it - it will be rewrited.