Browser version of word changes area codes

Recently, within the last 2 weeks, when using MS Word in the browser, area codes are automatically changing characters. I believe it is being caused by auto numbering.

Example: Typing (909) and hitting space after the ) converts it to (1).

Several users on different systems have experienced the same behavior. Confirmed the issue exists when using Chrome or Edge browsers. The issue cannot be replicated in the desktop app.