Xcode 12.3 editor deletes brace pair

The Xcode 12.3 editor is deleting both characters in a pair of sequential braces/brackets/parentheses with a single press of the 'delete' key, even though brace matching is turned off in the preferences.

Is there a new preference somewhere I can use to turn off this behaviour? It's extremely disruptive when typing quickly.
Xcode 12.3 editor deletes brace pair
 
 
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