I can also link directly to maul +2, but it does not show up in search, nor is it linked from the "weapon +2" page.
So my suggestion is to either make all those +1/+2/+3 weapons (and probably also armor) searchable, but I don't think you want to do that. I believe leaving stuff out of search results has been specifically added for these items. The next best thing would be to make items in the https://www.dndbeyond.com/magic-items/weapon-2 list into magicitem links. That way at least there is a way to see that the link exists without trying randomly.
The magic item is weapon +2 and I can search for it through the item search by specifying "weapon".
There is a list of weapons under it, on this page: https://www.dndbeyond.com/magic-items/weapon-2 and none of those are links.
I can also link directly to maul +2, but it does not show up in search, nor is it linked from the "weapon +2" page.
So my suggestion is to either make all those +1/+2/+3 weapons (and probably also armor) searchable, but I don't think you want to do that. I believe leaving stuff out of search results has been specifically added for these items. The next best thing would be to make items in the https://www.dndbeyond.com/magic-items/weapon-2 list into magicitem links. That way at least there is a way to see that the link exists without trying randomly.