No GPS in copter 3.5.6 RC1

Hi, I changed from copter 3.5.4 to 3.5.6 RC1 and now the GPS will no longer be detected.
Can anyone help with that?

Cheers

Not opening a new thread. Upgraded my Pixhawk v1 with NEO-M8N to 3.6.0-rc1 on ChribiOS and I get No GPS. Back on 3.5.5 NuttX 3D lock with 12 sats (indoor)
I even fired up u-center and tried 57600 baud and fiddled with settings on both the GPS and Serial_3 and GPS config in parameter list. Every modification works in 3.5.5 but I get No GPS on ChribOS…