CS8416 does not sync on external clock

Hello, I have build a CS8416/CS4397 DAC configuration in hardware mode. This is working fine.

My next step was to ad an external clock so i connected a 33mhz clock to omck that is routed to the clock to rmck (at no spdif input). So far so good.

But when i apply an SPDIF signal, the LRCK wont lock on the 33Mhz clock but does fall back to the SPDIF/PLL clock. 🤔

My best guess is that i also have to toggle the HW/SW mode of the CS8416 OR to set a register to "use" the external clock instead of the SPDIF regenerated clock.

So, how can i get the CS8416 (which is in HW mode), that it will use the external 33Mhz clock to lock the LRCK.

I like to use the external clock in CS8416 hardware mode. Can it be done?