Hi @Amālija Brūvere,
Thank you for posting your question in the Microsoft Q&A forum. After reviewing your steps, I tested this behavior in my own environment and observed the same results. The AutoCorrect option to replace two hyphens with an em dash works perfectly in the Word desktop app. However, in Word Online, even with the option enabled, the behavior is inconsistent. It doesn’t always work when you press Space or type characters continuously, and occasionally it works when pressing Enter to start a new line, but not reliably.
This appears to be a limitation in how Word operates in a browser. As a forum moderator, I don’t have access to backend tools or permissions to perform deeper technical checks, nor do I have the ability to modify or escalate product-related changes directly. And posts in this forum are not visible to the product team, so to make sure your feedback reaches them, I strongly recommend submitting it through the official channel: Word · Community

This is the official portal where your input goes directly to the product team and can be considered for future improvements. If you’ve posted your feedback, feel free to share the link in the comments, I’ll be happy to vote for it to help bring more visibility.
In the meantime, if real-time collaboration is important for you, you can still use the Word desktop app while co-authoring with colleagues. Microsoft supports cross-platform co-authoring, so one person can work in Word Desktop while others use Word Online, and all changes sync instantly. For details, see: Collaborate on Word documents with real-time co-authoring - Microsoft Support
In Word Online, click Editing in the top menu and select Open in Desktop App. When Word Desktop opens, make sure AutoSave is turned on. This way, even if you use the desktop app and your colleagues stay in the web version, you’ll all see each other’s changes in real time. And in Word Desktop, the AutoCorrect feature you mentioned will work as expected.
Thank you again for highlighting this point. Many other users may experience the same limitation, so this answer provides helpful information and shows the right way to share feedback, please click “Accept Answer” and kindly upvote it. Accepted answers are pinned to the top, making them easier for others to find, and collective feedback is a powerful way to drive improvements.
We truly appreciate your patience and collaboration.
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