It's either is not turned off or you've not deleted the cache.
First check the option again. Then delete the WOrdPress cache, then go to wpForo > Overview admin page, scroll down and click the [Delete All Cache]. If this doesn't help then there is no other solution.
In case you want to say thank you !) We'd really appreciate and be thankful if you leave a good review on plugin page. This is the best way to say thank you to this project and support team.