4DCAPE43 on Beaglebone Black

I’ve some problem with 4DCAPE43 and Beaglebone integration.
I read old posts for issue and now I’m be able to use 4DCAPE43-BBB on Beaglebone with Debian 8.1 (24/01/2016 - there is problems instead with the latest version 9.1), but I still have problem when I enable UART4. In this case the screen appear all black. If I look log with dmesg all cape are loaded correctly, no conflict is detected.
The only thing which I think it could cause problems are cts and rts signals of UART4 which overlap some lcddata signals, but if I look BB-UART4 overlay I think that this pins aren’t enabled.
Can you help me to figure out what the problem is?

Thank you in advance!