MCP2515 Not initializing

Hi,
I try to make it work a CAN bus with 2 MCP2515, 1 Mega 2560 and 1 Genuino MKR1000.
Connections are made this way:
INT - 2
SCK - 13
SI - 11
SO - 12
CS - 10
GND - GND
VCC - 5V.

The problem is that is not working. I tried coryjfowler, flori1989 and Seeeduino libraries. It's not working with either of them. I changed the CS pin to 9 or 10, the MCP's have a 8MHz crystal and modified in sketches, changed from 500kbps to 250/125kbps, nothing.

However, the sender seems to send some messages but don't know how, but the receiver is not receiving anything.
I attached a screenshot from coryjfowler library with loopback mode sketch.

mcp2515 monitor.jpg