Subdomain Issues

Forgive me, but I’m not the most technically savvy when it comes to web work…so I may ask an unanswerable question, but here-goes:

I have a website with a subdomain (https://rackandtackle.skyfallproductions.ca). It works just fine, however when I try to access or link to it by using https://skyfallproductions.ca/rackandtackle, my site title becomes “Page not Found” and my font-awesome icons fail to register.

I can’t seem to find a fix for this, and the error seems to be inconsistent. Sometimes it will load my skyfallproductions.ca page, sometimes I would just get a full blown “server not found” error.

Is there a way to force-redirect the link to change the active URL as rackandtackle.skyfallproductions.ca to avoid the issue?

Thanks in advance!