Bought my first boat this past August, it came with a Humminbird Onix 10 on the console and an 898 at the bow. I‘m having trouble with both displays when it comes to the si, di, and sonar. They were working just fine when I first got it. The charts work just fine. Any ideas, suggestions? Thanks.

either transducer or head unit. The only real way to be sure would be to connect a different transducer to the unit to see if its the same or fixes the issue

I wouldn't expect both units to go on the fritz at the same time. I'd check connections and the transducer.