There has been issues where Jagex have messed stuff up like this, but I doubt it since I haven't heard it elsewhere. But it could be, you never know. But to really find you should probably try Reddit or Twitter.
I got qbd pet at 3103 which has same droprate and same threshold so basically you're not much higher than that and it could happen in the next one or two. I'd just keep going
Rank #56 Overall. 8000/1****? Hard caskets stacked. 7000/8****? Elite caskets stacked.
31/37 boss logs completed - Ultimate Slayer achieved
Would you trust a Price-checking service that has bots running in W2 advertising themselves constantly? I wouldn't!