I didn’t realize this might affect Intel 12/13 platforms too.
@Morpheus636 re: relationship to other symptoms: To the extent this could be due to the EC, I wonder if BIOS 3.19 regresses this on 11th gen laptops too (emphasis mine):
Enhancements
Update Intel CSME package to 5.0.42.2235v2 Corporate.
Move to shared EC branch with 11th, 12th, 13th gen.
The two I have access to are still on 3.17 pending non-Windows installation method. It would be great if someone with 3.19 on a 11th gen machine could try to reproduce the resume-on-lid-close/AC power change behavior.