phone locked up when recieving SMS while suspended

I suspended my L5 running the 5.16.3 kernel:

$ echo mem | sudo tee /sys/power/state

Then a few minutes later sent an SMS to it. The display woke up and showed the last thing it had shown before suspending (which was Chatty running in phosh), and seems to have completely locked up. No lockscreen was shown, and it was unresponsive to taps, button HW presses, or SSH over usb network (on postmarketOS).

I don't have a way to get a serial console on this phone 😞