This is the screenshot of my user page:
Which obviously doesn't contain the link to its meta site whereas the meta site contains the link to the main site.
This is the third time I am typing this post. Before submitting I go to my user page to double check only to find that the problem does not appear anymore. That's why before this I discarded my post twice.
So what's the reason behind the link getting disappeared? And why does it reappear without any visible reason?
I am using Windows 10 v1903, Firefox v67. I think my connection is stable enough and I don't think I have any plugins enabled that could raise an error. I haven't hidden any profiles.
The reason could be that this is the first time I visited meta. In fact, I just checked it on another Stack Exchange site and it turns out to be true.