Oddly, there is no coreboot tracing from the attempt to resume in the log - it just shows the successful boot, then another boot later. This probably means the CPU is not coming out of S3, one way or another.
I noticed you said “Pressing any keys, won’t wake up the laptop” - you tried pressing (but not holding) the power button right? Librem EC does not wake for other keys on the internal keyboard.
Thinking out loud, having already rolled back all the way to EC 1.6 suggests it is probably not the EC firmware either, flashing the firmware also resets the EC so it is probably not the EC getting stuck in a state preventing wake / shutoff either.
When you suspend the system, does the keyboard backlight turn off and does the charge LED start pulsing?