Crosstalk on PCB: Why Does Trace B Mimic Trace A Without Decay? Inductive vs Capacitive

I'm currently testing a board that I did not design and unfortunately don't have access to the design files but while testing it I noticed a significant amount of crosstalk on one of the traces.

Trace A has a low frequency ~5kHz ~100ns rise time 0-5v signal on it and trace B has an induced signal on it that mimicks trace A. I'm trying to understand what type of coupling would cause this. I thought if it was inductive coupling I would see a signal spike at the transitions and then the signal would exponentially decay. I'm not seeing any significant spikes on this signal however and the level doesn't decay i.e. Trace B is an exact duplicate of trace A just attenuated.

I would appreciate any help understanding the cause of this, thank you!

Hi John,
Good day! How are you?

Are you sure trace A and trace B weren't accidentally shorted/connected [what does
a continuity test show?].
If not, then maybe the 2 traces were badly placed.
I think there is a PCB rule for that [for high frequency signals] I just forgot because
of my minimal exposure to board design.

Hope this helps.

Warm Regards,
Justin

Thank you for your reply. I'm good and hope you are as well!

I double checked the test equipment setup to make sure and nothing is shorted with the equipment and its not. The general rule that I've always been told is don't run non-differential signal lines parallel and if they must be parallel at least 3x the trace width between them. Unfortunately I can't see how the traces are run due to not having the design files and that this is a very low speed signal. My thoughts right now are perhaps something in the circuit design is allowing an alternative path of higher impedance for the signal to get through.

Thanks again for the suggestions!