Hard Pedal - no brakes - weird ABS feel What is going on

[PkB2014]

Had a scary incident this weekend at an Autocross event. Coming into the first turn going maybe 60mph, went to hit the brakes and the pedal wouldn't go down, just hard pedal and no brakes (or very little brakes, hard to know 100%) thankfully it was a big open surface and i just kept going into cones and a big water puddle, but avoided the course workers. After coming to a stop I pumped the brakes and they seemed to start working again, i made a couple start and stops to test and seemed ok, so i exited course. It felt like something was blocking the pedal from moving so I checked the footwell when I got back to grid and found a quarter. Thought maybe it somehow got lodged in there somehow to block the pedal, IDK. We then had a couple hours break and then I and my co-driver ran 3 more runs each later in the evening. We didn't get the "hard pedal, no brakes", but I did feel ABS pushing back on me harder than normal especially at the finish where we had to shut it down pretty quickly after hitting probably 70-80mph or so. We both felt something was off still. I was running Hoosier A7s for the first time, and had 315-30/18s up front with the 345-30/19s in the rear. So the F/R ratio was not exactly OEM.

2017 GTC with TA Group
Traction Control / ESC all full OFF

Anyone else had anything like this? Did the 315s in the front cause this weird reaction? I have another Gen V Viper friend says this happened to him a couple times and caused off-track incidents and he was running standard 295-30/18 fronts. Kind of scary to think this is a normal failure. Any advice on this is appreciated. I may swap back to Kumhos and run another event to confirm the tires are not the issue, but IDK, brakes are kind of important. I want to say I had another weird brakes issue a few months back when i first ran the Kumhos, but i brushed it off thinking I did something wrong, and I never had any issue since. But now looking back maybe it was the start of this issue.