FYP and explore page not showing nsfw/sensitive content on new account

Sensitive content is set to ‘more’ in the content preferences tab, I am over 18, and another account that I own (made years ago) displays plenty of nsfw content.

Is it because the account is new? Has few followers? Is this some sort of spam filter or protection against sexual algorithms?

I can’t find any info about this online, and I have tried creating separate accounts to no avail.