[Sephiroth]

It looks to me like the incoming RG6 cable (the thick one) goes to one Omnibox and is then cascaded to the other.

From a power perspective, that doesn't matter because you are close to the cabinet. If you are on the incoming Omnibox, then c. 4 dB is knocked off your power and the same again after your inside splitter. If you're on the cascaded Omnibox, add a further 4 dB.

But noise is another matter. If degradation of the splitter has occurred in either or both Omniboxes, then you could have problems that could well follow weather patterns or temperature.

I don't necessarily want to send you down this route, but when I had non-obvious problems, they sent a Senior Tech who checked out all the external wiring, the Omnibox, the splitters - renewing much of it.