New Creator Store links (e.g. https://create.roblox.com/store/asset/15507630959) are filtered and replaced with hash symbols. See “Plugins” section:
The old library links (e.g. https://www.roblox.com/library/15507630959) are not filtered, and are fine to be posted along with any other www.roblox.com and devforum.roblox.com links. See “Plugins” section using old library links:
My initial thoughts were that it might be the “store” or “asset” parts of the URL causing issues, but even just https://create.roblox.com on its own gets filtered out.
Expected behavior
I would expect all *.roblox.com links to be acceptable and pass the filter (assuming the alphanumerical parts of the URL would pass the filter on its own).