It’s not hard to find good sources stating Facebook still advertise tobacco, though you appear not to have noticed the links stating this fact. Here are some more recent links.
https://www.theguardian.com/business/2020/mar/17/british-ame...
https://www.independent.co.uk/health_and_wellbeing/big-tobac...
“British American Tobacco circumventing ad ban”
“Smoking giants are flouting rules set by Facebook and Instagram”
As always, regardless of the digital or print medium, Big Tobacco (& others) have always tried to flout the rules. Same goes for Alcohol and Gambling ad bans.
Yes, it’s proving hard to enforce a ban, but are we supposed to be sympathetic to Facebook?
‘On Instagram, Big Tobacco’s influencers post glamorised images of vape products with hashtags such as #idareyoutotryit and captions such as “feeling Vype AF”.’ (From my link).