I think it is not very easy for read.
I agree. You may want to post gerber files in addition to provide a clearer view. I don't agree however, that it's a copy of the Eval-Board
layout. If I understand right, you also have copper pour on both sides, but it's not that continuous. Furthermore, even a continuous ground
plane hasn't zero impedance. It can have "modes", particularly if you inject differential currents between different points at the ground
plane. Having the ground plane partially cut up, as apparently in your layout, reinforces the risk of ground plane resonances.
For the coax output, you should absolutely have a 50 0hm series termination, otherwise it acts as a critical capacitive load respectively
a transmission line resonator. 1 m coax cable with one end open (oscilloscope side) and one end shorted (OP side) is a fine λ/4 resonator
(about 50 MHz resonance). Adding the series resistor gives it sufficient low Q to disable it as a resonator, respectively isolate the
capacitive load from the OP output.