When you generate a Superflat world with at least one layer being Sculk Sensors, the Sensors will not trigger. Newly placed Sensors will work, but the ones generated with the world do not.
Environment
Arch Linux, 64-bit. GPU: AMD Radeon RX 5500M, CPU: AMD Ryzen 7 4800H, 16GB DDR4-2666. Java Version: AdoptOpenJDK 8u251
Duplicates MC-207251