Okay, I went into manage and checked the Multisig settings, for some reason, the multisig address was empty and so was the owner address which is my address. This is odd because the Approval Process was used previously to deploy the contract successfully.
Nonetheless, after I did the above, I was able to run into a different issue altogether:
The address in the error prompt is the multisig that was used as part of the approval process for deployment. I assumed that that address would be the owner of the contract and thus can create Transaction Proposals.
But, when I checked the owner of the contract, it was this address instead:
It looks to be some OZ proxy contract that is used to perform deployments.
I checked my constructor code and I use _msgSender() instead of msg.sender, I thought this way would preserve the original msg.sender:
I ended up with the same exact result where the owner is the same as before, that OZ proxy contract. Even if it did work, I would've been worried about the lack of compatibility with meta-tx relayers anyway.