Help me with some troubleshooting steps.
I have tried all basic steps

 

You are experiencing voltage drops across traces because your traces have non-zero resistance and when current flows through a resistance, there's a voltage drop.

What do you consider "basic steps"? We are not mind readers.

Have you calculated the resistances of the traces in question? Have you determined how much current is flowing in those traces? Have you calculated the expected drop across those traces?

I would assume so, since those are pretty basic steps.

But it might help us help you if you didn't keep it a secret.

What voltage drops are you seeing? How much current is flowing? How big are the traces, in terms of length, width, and thickness?

Are the traces experiencing the drops carrying DC current, or are these high-frequency signals?

How are you measuring the voltage drops?

 

hi krut
This PCB design PDF may give you guidance.
E

 

Very early in my career I learned the hard way that PCB traces have not only resistance, but also inductance. In addition, a PCB trace can also function as a fuse to interrupt excessive current.

 

In the distant past I was given the job of determining why a 16-bit DAC, used for calibration of a test set, had small voltage errors for certain output voltages.
After a lot of measurements on the test board with a high-end HP voltmeter (likely 6 digit), I determined that the small change in digital currents from various combinations of the input logic signals was causing a small voltage drop on a critical ground trace, and thus the observed error in the output voltage.
So I soldered a good sized copper wire along the length of the offending trace, removing the error.