DV360 Bid Strategy Pacing Issues: Why is my CPA spiking and spend dropping overnight?!

Seriously, I am completely stuck and have been tearing my hair out for the past 12 hours trying to figure this out. My critical lead generation campaign in DV360, which has been consistently performing beautifully for months using a Target CPA bid strategy, suddenly went completely sideways overnight. We're talking about a campaign that was hitting its CPA targets perfectly, delivering thousands of qualified leads daily, and now it’s just... broken. The core problem is that the bid strategy pacing seems to have entirely collapsed. My CPA has skyrocketed to five times its target, and daily spend has plummeted to less than 10% of the allocated budget. It literally happened overnight; one day we were crushing it, the next morning I wake up to alerts screaming about underdelivery and an unsustainable CPA. This isn't just a minor fluctuation; it's a dramatic, catastrophic failure that’s costing us a fortune in lost leads and wasted budget. I've been through every single setting multiple times. I've checked for budget caps, ensured creatives are approved and active, reviewed targeting settings for any accidental exclusions, and even double-checked policy violations, but everything appears to be exactly as it was when it was performing optimally. I’ve tried adjusting the bid target up and down by significant percentages, switched temporarily to a Maximize Conversions strategy just to get some spend going, and even fiddled with frequency caps, thinking maybe we hit some saturation point, but absolutely nothing has worked. The campaign just sits there, barely spending, with the bid strategy reporting ridiculous projected CPAs. This is crucial for our overall DSP optimization efforts. The symptoms are clear: campaigns are not spending even a fraction of their daily budget, the reported CPA is astronomically high, impression share has dropped off a cliff, and when I look at the bid strategy pacing charts, they are just flatlining or showing erratic, nonsensical behavior. It’s like the algorithm completely lost its mind or hit some invisible wall. Has anyone encountered such an abrupt and severe breakdown in DV360 automated bid strategies before? What could possibly cause such an overnight collapse when absolutely nothing was changed on our end? Are there any advanced troubleshooting techniques or diagnostic tools within DV360 that I might be overlooking to understand why the pacing is so utterly broken? Could this be related to a silent platform update or some backend change that isn't immediately visible? And most importantly, what's the best course of action for managing or effectively resetting an automated bid strategy when it's in such a catastrophic state and refusing to spend?