This reminded me of an anecdote from maybe 6 years ago. I was setting up and testing a small network and a couple devices to install for a customer, let's say the subnet was 192.168.2.0/24.
Weird things were happening, I was being lazy and wasn't directly connected to the network, may have setup a VPN between devices somewhere; can't really remember. But pings would sometimes drop or blow out to 100's ms.
I eventually ended up disconnecting that network entirely, then the pings continued and got more stable?? WTF! I need we didn't have that subnet in use, even checked before setting it up. In the time between checking and the issues happening, someone in Sydney somewhere had stuffed up on their router and exposed there LAN to the internet without any Firewalls, just available.
Scanned and found all the IPs in use and in them found a printer. Connected to it and printed a page saying I'm from company XYZ and found all these devices available, and to either contact their IT and resolve it ASAP or my company to help. About an hour later it seemed to be resolved.
Can you kick up the 4d3d3d3?