Unconfirmed word on the street, so to speak, is that the Ukrainian air defenses are having a hard time tracking and then locking onto the drones for varying reasons such as low infrared/heat signature(s), etc.
What is probably needed are massed anti-aircraft guns utilizing fragmentation munitions.
Admittedly, all ongoing speculation.
Still reading from varying sources (some from sources in Kyiv and in the Donbass region) on the matter of drones, how they are changing the landscape of warfare, and how they can be countered with effective air defenses.
“What is probably needed are massed anti-aircraft guns utilizing fragmentation munitions.”
Something along the lines of the Russian Pantsir-S1 SA-22 Greyhound air defense missile gun system.
including Europe,..... to ensure its country's winter heating season.".......
Ukraines going to also suffer..