"Last_heard" date and time is not accurate

Hi all,
“Last_heard” is not accurate when I call from my web app
particle.listDevices function (Particle API JS) but is not accurate also on mobile app and on web console. Correct value appearing when I just “click” device (mobile app ios, console) and then go back to device list is remaining good as long as I do not refresh web page or mobile app but as soon as I refresh it, incorrect date and time is back.

I found couple topic here and here about “last_heard” they are pretty old but there where also git hub issue filled which is closed as solved but is not !

@Dave, @rickkas7 could you guys assist with this please ?
I’m interested specially with Particle API JS (Javascript SDK)
Thank you in advance,

Never mind I get this things done around, instead of listDevices(), (which looks like is useless for timestamp) I used getDevice() on each dev separately to obtain most accurate time stamp