Hi Arthur,
It’s a phpBB system issue. In this issue, you need to contact with phpBB support https://www.phpbb.com/support/ Because it’s no a theme/style issue.
Please Note: We are providing the phpBB theme/style by customizing phpBB default theme/style.
So, we are unable to assist you on phpBB system issue.
Please learn more about our support policy (item support includes & not includes), here https://www.themelooks.com/support/support-policy/ before post a topic or ask a question.
Best Regards,
ThemeLooks Support Team