I just used the reset button on the device itself again (instead of the menu) and reconfigured it from defaults.
It seems to be more reliable for about 12 hours, but there's still appears to be some packet drops after that.
I couldn't find a time-of-day correlation for the packet drops in the past several months.
Nor could I find anything correlating to what the client was (iphone, mac, android, etc).
I'm wondering if it might be a power supply/heat issue.