You know it's serious when Parm Pap doesn't make a non-sensical post....
I think the curse was done by the Rocky Express fan personally.
Obviously they'll have models, but I'd be surprised if those systems have a way of determining a probability for a rollback / stall / valley. And even if they did, I'm fairly certain they would never approve anything where the chance for stalling was higher than a fraction of a percentage.
Plenty of rides have stalled in places; it's something which happens. It's not a common occurrence - and certainly not a 'teething problem' - but it can happen. Other Thorpe coasters have stalled during empty-train tests: Colossus on its final turnaround, Saw on its overbanked turn (and the bottom of the first drop), Stealth atop its top hat. There's plenty more examples around the world. It happens.
The slower running of the stall seems to have occurred after the first prolonged closure, with the lift hill seemingly being slowed down slightly. That might be having some knock on effects.
I see plenty of people saying they didn't test it enough, etc. That's bull. They've tested it plenty, but there's clearly been other factors which have happened too.
I guess Thorpe are nearing a point of damaging limitations. Do they reopen asap, and keep papering over the proverbial cracks until closed season? Do they have an extended period of closure to fix the issues with Mack? Something else? Who knows.
As has been said here, other rides have had difficult first seasons which are later forgotten about. I'm sure Hyperia will be the same. But for now, it's a difficult wave to ride.