Ex3400 or Ex2300 ships with 15.1X53-D50.
With this code LACP Dot1x ,DHCP and other timer related protcols wil not work.
The Root cause seems to be system clock showing incorrect time 2038.
Solution and workaround is documented in below KB313588 article
https://kb.juniper.net/InfoCenter/index?page=content&id=KB31358&smlogin=true&actp=search
If its a Poe device then best Junos version is 15.1X53-D55 which includes the above fix as well.