When viewing a node there will be some threads which show pagination i.e. ...    when hovering the mouse over the title row. However under some random circumstances some threads will not display the pagination (they have more than 1 page) and you have to zoom down to 90% and then get back to 100% to fix the problem and see the pagination for every thread properly (when applies).
I can't share the link of my forum in public but if the devs want to see the problem in action please start a conversation with me so I can reply there because my account is limited (I can't start conversations).
Btw this bug report by @ibnesayeed might be related although my site isn't RTL.