What is going on with these SPI transmissions?
I believe the bus you're looking at simply has multiple slaves. They share MISO, MOSI and CLK but have dedicated slave select lines for each of them. The ENABLE signal in your waveforms is one of those slave selects. You can look for other slave selects on the master chip pins if you want to test this hypothesis.

Note how signals seem to change polarity from one slave to another (most noticeable in the clock). Maybe different slaves use different SPI modes.

The waveforms appear to repeat with a certain period which would indicate that the master queries slaves one after another in a loop.