Betfair matched amounts - an observation from today

[weemac]

I laid 2 bets tonight on Napoli vs Sassuolo under 3.5 goals. They were both £6 lays, one at 2.96 and one at 2.94. A large back came in at 2.94 which matched both bets, and no other volume was traded at that time but my 2 bets. Strangely, the matched amounts showed as £6 for each bet, even though betfair always doubles the actual bet amounts for reporting purposes.

I saw the £6 traded amounts reported both on betfair's own website and on another vendor's software, which also shows exact amounts traded. A few minutes later the 2.94 bet did indeed show up as £12, and the 2.96 was over £1,000 because a lot more was subsequently matched at that price.

Has anyone else observed this delayed 'doubling-up' of reported volume, which until now has always been instantaneous?