Ok. On the MSO, the analog waveform seems to be slew-rate limited / filtered to be something between a sine wave (which I had originally assumed) and a triangle wave.
Could there be excess parasitics with the cabling setup? It sounds like from the original posting that both instruments were on the signal generator at the same time. That is, the yellow trace on the MSO may be showing the actual waveform going into the logic analyzers.
1. Can you try one instrument at a time?
2. It looks like the source impedance should be 50 ohms. What are the cable and input impedances of the instruments? How long are the cables, what type, etc.