@requiem That is when you hold an all-hands meeting, citing specific sequences of code and the impacts that code has had on your time and ability to deliver on your deliverables, and the economic impact to the company. Make sure to emphasize the economics. Managers love dollars and hours.
Then, stipulate a new rule: he who uses Copilot fixes Copilot's shit. Using git blame or your VCS's equivalent functionality, it ought to be possible to determine who injected the defect. Halt the build pipeline until it's fixed.
This will get people's attention very quickly.