Here's what happens:
@[member="Florin Armetta"]
@
Florin Armetta
As you can see, the top one properly uses the Mention feature. This can be confirmed by seeing a little summary of your profile page. The bottom one does not properly use the Mention feature. It's simply a link to your profile page.
To reproduce the instance of where one's profile is simply linked rather than Mentioned,
one has to have copied and pasted the formatted link into the WYSIWYG part of the post editor.
In the case of your thread, you are not being notified due to user error. They are copying from previous posts the Mentioned name and pasting it into the WYSIWY mode of the editor. The site does not convert links into Mentions, only plain text.
Here is a pictorial example:
This is how it should look when you hover over a properly Mentioned name:
This is how it should look when you simply have a properly linked profile page, yet one not mentioned:
These are the steps to reproduce linking a profile but not mentioning it:
Select and copy the Mentioned profile name.
Paste the profile name into the WYSIWYG editor and post. You can tell this is the WYSIWYG mode of the editor when links are represented by blue font and underlines as well as colored formatting buttons.
To actually mention a profile though while copying previously mentioned names, repeat the process but change the mode of the editor to Source. You can tell this is the Source mode of the editor when formatting is represented by Bulletin-Board-Code and formatting buttons are grayed out.
I hope this helps you. I understand that this is an annoying thing to deal with, but this is how the software works. I suggest forwarding others dealing with issues pertaining to Mention notifications to this post.
PS: It's funny and it might be because of the type of thread this is and how the best answer has already been chosen, yet in the case of
this post, I cannot actually Mention you. Period. Even using the proper format for mentioning a member as well as the BBC code, the side refuses the create the link. In this case, it would be site error - the user has done everything properly yet an error still exists.