I don't know if you ever got this problem resolved, but I had the same thing happening on Debian buster/sid on a ThinkPad T460. The output of my dmesg wasn't identical to yours, but importantly, it had the same

ACPI: EC: event blocked

line. Per this thread on AskUbuntu, I disabled XHCI as a wakeup trigger in /proc/acpi/wakeup:

$ grep enabled /proc/acpi/wakeup | cut -f 1
LID
SLPB
XHCI
$ sudo su
# echo XHCI > /proc/acpi/wakeup

and that fixed it for me. Oddly, this was only supposed to matter if you had USB devices plugged into the machine, but I most certainly did not.

I don't know if you ever got this problem resolved, but I had the same thing happening on Debian buster/sid on a ThinkPad T460. The output of my dmesg wasn't identical to yours, but importantly, it had the same

ACPI: EC: event blocked

line. Per this thread on AskUbuntu, I disabled XHCI as a wakeup trigger in /proc/acpi/wakeup:

$ grep enabled /proc/acpi/wakeup | cut -f 1
LID
SLPB
XHCI
$ sudo su
# echo XHCI > /proc/acpi/wakeup

and that fixed it for me. Oddly, this was only supposed to matter if you had USB devices plugged into the machine, but I most certainly did not.

EDIT: Never mind, I forgot about the part where you tried disabling every line in /proc/acpi/wakeup.