How to disable automatic updates in this version?
Usually that option is present under File >> Account, but in this version that specific option is missing.
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I have not installed this version, so the information I will provide you with is what I have read elsewhere.
Unlike Click2Run editions, Volume Edition (VL) does not offer the application update through Account (File -> Accounts -> Updates).
To get updates for the Office 2016 VL version, you must enable "Get updates for other Microsoft update products" in Windows Update.
I guess doing the opposite, that is, disabling updates for other MS update products would solve it.
Try it and tell us, while we wait for opinion of author of the thread.