Chateau 5GSA N38@40Mhz doesn't work

Hey all,

I’m working on 5G SA Networks, and I’ve yet to connect the Chateau 5G (this guy : S53UG+M-5HaxD2HaxD ) to our network when using a 40Mhz bandwith on the N38 band.
It works fine on N38 at 20Mhz.

I am running ROS 7.11b2, my modem has this firmware installed : RG502QEAAAR13A03M4G_01.001.01.001

Am I missing something here?

Best Regards