when exiting the “edit”, anki asks, “Undo changes?”
While usually what is customary on most platforms, the question is the opposite “save changes?”
The plus is that you can continue exiting and save the changes, while in the current state, in order to save changes, you must cancel the exit, save and exit again.
The most recommended is what is on most platforms today: “Save changes?” When the options are: “Save” “Don’t save” “Cancel”.
Logged on improve confirmation screen when closing add dialog · Issue #2282 · ankitects/anki · GitHub
@dae Thank you very much for this application!!
I think the default should be on “save” and not on “cancel”
The explanation is simple:
There is almost no need to go into editing a card template, if not to edit the template
Therefore, it can be assumed that if a change was made, it was made on purpose, so the default should be save.
Cancel is the least likely to cause data loss: changes won’t be accidentally discarded, and changes won’t be accidentally saved.
I don’t think that’s a safe assumption 
We even have an FAQ for it.
https://faqs.ankiweb.net/extra-characters-appearing-on-cards.html