Max Date on Opportunity ID

Hi,

I'm trying to filter a report to just show the latest date figures were amended against each opportunity.

I've tried using MAX(Modified UTC by Opportunity ID) formula on the Modified UTC field but that didn't filter out the older records.  I tried to filter that field with the forumla to TOP1 but that didn't return any results.  I tried it with RANK and a filter which didn't work.

I need to just return the latest record per opportunity as it will add up all the amendments and show incorrect figures.

I'm wondering if it's becuase I'm trying to use data from two different tables?  In my screen shot everything up to opportunity ID will come from one table but all the Modified UTC and financial records onwards come from the other table.