Ping sensor units for measure for round trip times

Just noticed something interesting with my ping sensors.

I have a number of ping sensors for wireless access points, my router and some other key devices local to my network and also have some other sensors for some key web sites.

I have noticed that with the ping sensors local to my network, they are returning quite high round trip times (30+ ms). When I SSH to my home assistant machine and ping the same IP addresses, they are all sub-millisecond response times - around 0.3 ms which is what I would expect for wired devices on a local gigabit network. So before anyone says “take a look at your network”, I believe that my network is fine. Round trip times for devices I would expect to be higher (e.g. external web sites) appear to be reporting correctly and around what I get when I manually ping them from my HA machine.

Just wondering if anyone else has noticed this, and whether or not the ping sensor might be converting sub-second round trip times from milliseconds to nanoseconds? I have had a look at the code, and it does not appear to do a conversion, but then I am not exactly a programmer.