This issue is currently under [url=https://twitter.com/BungieHelp/status/1534610730879549440?s=20&t=gOWltFTGKR849_me-VFXjw]Investigation[/url]. It was also mentioned in the recent twab. A fix is on the way. While you wait, you can click [url=https://www.bungie.net/en/Forums/Post/261265116]Here[/url] for a thread I made explaining a temporary fix for this issue.

Even though this is a super annoying bug, here's how I managed to get around it: 1. Open the transmog menu. 2. Navigate to the piece of armor and the appearance to be unlocked. 3. Place the cursor over the item you want to unlock. 4. Wait. Wait until the on-hover tooltip changes to tell you that you can now unlock this appearance. 5. Press and hold your mapped unlock button. The progress bar on the bottom of the tooltip should complete. 6. Keep holding down the button. 7. After some more waiting (your mileage may vary here), the appearance gets unlocked. I can't really deduce how or why this works, but it's almost as if there is a polling error with the database somewhere.

This is known bug [i]"We are investigating an issue causing players to be unable to use Synthweave to unlock new Armor Synthesis ornaments from the Appearance Customization menu. Players can work around this issue by unlocking the armor ornaments via individual armor previews quickly after selecting to preview their appearance."[/i] https://www.bungie.net/en/Explore/Detail/News/51446

Same! I am not able to unlock any ornaments. Sometimes it loads the entire way but it won’t actually unlock it.