Was it in Painwheel PF? If yes, then it's not a bug. Diva's SA drains a certain amount of Meter points, not certain percent, but PF modifier seems to charge opponent's meter in a percent-based way. Due to this the amount of Meter you drain from BB3 is lower than Modifier-provided Meter gain, that's why it stays charged.
Compare it to Bella's Meter reduction on throws. Merry Go-Rilla lands only one blow and therefore reduces more Meter than it generates, but Pummel Horse deals several hits and therefore generates more meter than it reduces.