4.0.3 Retention Issue with FSDb

I know 4.1.0RC is now released, but hitting an issue with 4.0.3 where one of the advised issues was resolved.

NTA 4.0 Service Release 3 
"NTA Service or NTA Flow Storage Service occupy high amount of memory for long retention periods and/or high amount of stored flows"

I'm seeing that although my retention is set for 35 days, yet when dynamically querying the FSDb from GUI, it reports 62days / 98.5GB for the FSDb.

Anyone else seen a repeat of this - or is this a slight difference in interpretation of resolved issues mebway / cobrien?

I've created Case #716319 - "FSDb retention period different to that configured." just incase it's something else causing it or does 4.1.0 definitely tick that box?

Thanks