The weird part is that the toggle switch is kind of stuck in the on position and doesnt offer any tactile feedback.
Is the switch toast? These are vynco outlets that are just a few years old.
As a former Sparky's labourer, that sounds to me like something you'll want to replace sooner rather than later. If there is any sign the switch is getting warm, speak to a Sparky promptly.
Sounds like the contacts inside the switch have been welded together due to the high current draw caused by the faulty appliance before it tripped the breaker.
Absolutely would say it's buggered. Don't even try and use it.