I'm having an intermittent wireless problem on Ascii. On occasion I
lose connection to an existing 802.11 5GHz wireless network or cannot
reconnect after resuming suspend. It happens only occasionally and I
can't yet get it to consistently fail or fail on demand.

When this happens, the ongoing output from wpa_supplicant says "wlan0:
No suitable network found" and "iwlist wlan0 scan" finds nothing.

One thing that does work consistently is to plug in a 3G/4G modem during
the wireless failure. Before the modem finishes booting the wireless
connection is reestablished. What should I be looking for to try to
solve this on my end?

Regards,
Lars