Here’s a thought. It could be your friendly tire dealer. The reason I say this is that we used to take our Toyota to one particular Toyota dealership for routine service. On more than one occasion they would find a nail causing a flat needing repair or replacement.
Hmm. This is bad. Then one day my wife caught the service advisor on the phone with another customer telling them that their car too had a flat. It all seemed so much more than coincidental.
I have heard of that exact syndrome, including when a new tyre repair started up, and there was a rash of punctures all around the local streets.