Grid export value

can anybody shed some light on why my grid export value
As shown on the GivEnergy app is higher than the value shown on
My octopus app in the outgoing section, ie. 7kw export - 6.25 received according to octopus.

Probably due to the sampling intervals which mean that gaps between samples are over or under estimated. People in the forum seem to particularly notice it overestimating in changeable spring or autumn weather as clouds moving quickly can mean that sun intensity and shading on the panels are constantly changing.
For a simple example, you measure every five minutes and are generating 1000W at 12:00hrs and 1005W at 12:05hrs. So you might think you had generated 83-84Wh in that interval. What that doesn't account for of course is the three minutes the sun went behind the clouds and you were only generating four or five hundred watts.
The Octopus meter is therefore always the definitive source of truth for actual import and export usage. When it comes to home consumption the GivEnergy metering is the only show in time - at least for periods when you are self consuming from panels or batteries. The Octopus meter will just be showing zero then.

pwdst thanks for that👍🏻