How do I mark all post read on a mobile/tablet?

if you have problems with 'new content' linking to old comments

you may need to 'mark all posts read' 

on desktop pc it's easily found - its the 'arrow' next to the 'new content' link

however on a phone/tablet its a bit harder

you need to hit the hamburger menu

then as per the image below

hit the 'tick'

that will lead to all content being marked read and hopefully kick you 'new content' stream back up to speed