Ryder125 CA is a bit more sensitive than others i have tried in the past
Your menu issue especially if screen has gone completely blank can only be resolved in one way which is return and get a replacement from them.
I had the same issue with my 551r the very first time i switched on i couldn't turn my OSD on, then my dealer (A Very nice and knowledgeable guy) told me that he will send it for repair/replacement and they changed the whole board for me cuz changing whole board was easy then just the HDMI board.
As a best practice to all those AVRs (I do the same with my Anthem as well) never change (plug in/out) HDMI cable from the AVR while it's on... best is to completely power off the AVR (from back power) before you attach a new HDMI cable or take off one. It may sound strange but i have tested it with both Anthem & CA.. seems like these AVRs are more sensitive to these things than their jap counterparts.
Sure you will like the SQ more and more as the breakin process will complete i have tested/used 2 CA AVRs one which was new (no break in) and one fully breaked SQ was very different.
For your missing sound again i think this is an issue... i know CA takes a good time (more than others) to switch & lock HDMI (Audio & Video both) but i never experienced the missing sound.
As i told you before as well... out of all the areas surround is the weakest in CA but with good manual settings you can get good surround effects so shouldn't be a issue.
Don't lose hope... despite all these CA Azur AVR is still my top favourite un matched SQ with best Vocals ... So enjoy after you return this bad unit and get a new one