Using a teensy 4 I have tested a breadboard circuit with 3 spi slaves and replicated the connections on a perfboard.
On the breadboard everithing works as supposed but on the perfboard something is interfiring with sck: two connectors works fine but if I try to connect a cable to the third spi bus became inutilizable.
Connecting a lose cable to sck on that connector and touching it break everithing.