Setting the CName to my forum address links my subdomain to a completely unrelated site

I've been trying for most of today to link my subdomain to my forums, about seven hours now. I purchased the domain name vindictusmanual.com through the web host biz.nf last year, and I am now trying to link a subdomain of it, forums.vindictusmanual.com, to my forum at vindmanual.forumotion.com.

When I set to the CName of the subdomain to vindmanual.forumotion.com, instead of directing to my forum, my subdomain takes me to oceanforums.com, a site I am completely unfamiliar with. I am baffled as to why this is, and a friend assisting me with figuring out this issue experiences the same redirection. I have checked over a dozen times on the spelling, and this issue still persists.

I have tried setting it through Cloudflare, and through my Web host itself, both result in oceanforums.com. Here is an image of what the setting I applied looks like on each:
Biz.nf Domain Manager:


Cloudflare:


Is there some weird thing on the forumotion servers causing this strange redirection? It's making it absolutely impossible to attach the subdomain to my forum.

The steps I have followed were based on this thread:
https://help.forumotion.com/t7021-cname-redirect-an-extern-domain-name-that-you-own-to-your-board

Any help would be appreciated, I am exhausted and completely out of ideas on what could be wrong.

Hello,
Have you added your custom domain through the admin panel as well? You can do this in ACP (admin panel)-->General-->Forum Address--->Personalized Domain name->Type the custom domain name url in and save. This should compelete the redirection to your forum.

-Brandon

EDIT: The situation has resolved itself, and I think I understand what happened. For future reference purposes, I'll try to super tl;dr what my theory is:

1: I changed my forum address from vindictus.forumotion.com to vindmanual.forumotion.com.
2: An hour or two later, I tried to connect my subdomain to the forum. Cue mass weirdness.
3: Just now, around 12 hours after the forum rename, it suddenly spontaneously works.

Perhaps the name change just needed to propagate, despite how it seemed to apply instantly?

I was just now able to successfully apply the subdomain and it functions properly. You can mark this solved. Thanks for your input nonetheless, it did lead me to start suspecting.

Original post below:
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When I try to enter forums.vindictusmanual.com into the field in the ACP, it doesn't work and I get this result:



I have included a second browser in view to show that a CName is indeed still configured to the subdomain.