RT-AC88U Packet Loss and High Latency

I have an RT-AC88U running Merlin 380.68_4 and I'm experiencing up to 15% packet loss and latency as high as 500ms pinging the router from wireless clients on the LAN. This wasn't happening for the past couple of months, but started in the last week or two. I've tried every single channel, 20 MHz channel, 40 MHz channel, 20/40MHz channel. The CPU load on the dashboard is always between 0 and 1% and the bandwidth being used at any given time during testing is nearly 0. I tried rebooting the...

RT-AC88U Packet Loss and High Latency