Review indesign - updating the document and losing comments link

My client was making comments on a piece of artwork using Review, I needed to update on the of pages whilst they were still working on it and as a result all the links to the comments were lost. We can still see the comments down the left hand side but they are no longer highlighted on the document itself.... consequently, they've had to restart all the amends again! 

It would be helpful for this to be addressed going forward.