The last few months my network has been unstable and the CPU is always near 100%.

It was not like this before, we never had issues like this when I installed the deco units in Aug 2023. I have 3 deco X55s, one connected to my modem, one connected via wireless, and the other hardwired. I have the same 11 devices on my network. My washer and dryer, a few cell phones, 2 tablets, and the rest are roku tvs.