Roon seems to be very greedy with my bandwidth & system resources

@Snowdog
I feel sorry, but I can only tell you what was suggested to you in this thread several times before:

I’d put that device in bridge mode as well and look for a decent router. It doesn’t even have to be expensive, you could find something on the used market.

That’s because I did a quick search for your device here in the community.
I want to encourage you to read through it completely and consider the following: