I can confirm that all photos load instantly on the link you provided using Safari and like you, I am on OS 15.7.3.
I would recommend removing MalwareBytes as it does contain a VPN. I don't have any problem with MalwareBytes when doing the free one time scans, but would not have it running constantly on your computer which is what it does when installed for constant monitoring. I think others would agree with me, but will let them speak for themselves.
One other thing I should mention on the link you posted is that they are partnered with Google to provide them data of your activity on the site when you are signed into a Google Account. I don't like this monitoring and data harvesting that is done by Google when you are signed into the account. When you are not signed in with a Google Account you will see a prompt to use the Google Account to sign in, which can be dismissed. Otherwise you will be signed in automatically, which is likely being done by Chrome, and in my opinion that is a privacy concern where Google is using you as a product to sell your information to advertisers. I would not recommend being signed into a Google account, and even for Google searches, in the upper right corner you will be able to see if you are signed in with the option to sign out.
Anyways, we are always here to help.