Darf ich auf meinem Balkon Brownies essen?

Also, what about the back side of the barrel? Who is producing that oil?

Also Logseq.

The same applies for various password managers.

That does not sound plausible to me. Typically, your own computer would be behind a router that is either doing NAT or has a firewall (probably the former). Any incoming traffic would be directed to the router without any chance of reaching your computer. Whatever you saw was either outgoing traffic or incoming traffic in response to connections initiated by your own computer.