Are you using official Traccar Client app? Android or iOS?
Also sometime there is difference in time between Location Update Time and actual Device Time.
Bit of modified version of it. No change in core logic.
Using Android version of it.
Time value is reported directly by the operating system, so if it's incorrect there must be some issue with the phone itself.
This is very strange got this issue on one device. GPS location device time is shown as 1970 -