SOV rating 100% at down time but no upgrade after update

I am used to ratting in a system that has all the upgrades and I frequently battle to keep the MI at or above 100% just before update. Several times lately I have got the MI to 100% in the hour before update and I even once got it to 13% before update but after the update is over, no additional Hordes.

Clearly it isn’t a simple threshold of achieving 100% of level 5 and getting more Hordes because that doesn’t always happen so is it an average of the last hour’s index before update or some other criteria for getting the extra Hordes at update when you pass 100% of level 5?

as far as i know it g oes down by server tick and thus you can’t be on the mark on the last hour you need to be%10 above it to be certain.