@ Ianlee I don’t know what you are measuring, but it is not what you think it is. The last picture you sent showed a waveform with a cycle time of ~1500ns, or 1.5us. I did the math and that does not match a frequency of 100KHz or 10KHz. I have attached a picture of a 1.5us cycle time square wave, as you can see the frequency is 650KHz.
The Saleae picture shows that CS looks right for the signal, so the clock frequency has not been set to why you think. However, that doesn’t explain the MISO line (MOSI is matching the clock, so probably okay). After thinking about this more it is likely that there is a very cold solder joint and you are picking up a lot of noise. A resistance measurement is a good way to check this, but the pressure of the probe might be enough to make the connection good for aw while.
Just for fun, I took a capture of a 2.6V 650KHz signal on one wire of a 200mm ribbon cable and another channel on the unconnected wire next in line. The yellow trace is almost 600mV and looks almost identical. The 1V you are seeing is high for something completely disconnected so I would expect there is some connection
So, you probably have something not connected on one end.