[Bug] crkbd: keyboard unresponsive after enabling combos

Describe the Bug

My keyboard is a crkbd v3 (pro micro), with no OLED / lighting.

Following the documentation at https://qmk.github.io/qmk_mkdocs/master/en/feature_combo/ , I tried enabling combos on my keyboard. Unfortunately, it renders my keyboard unresponsive. It compiles correctly and flashes, but after it refuses to work (ie, I plug it in and no input is registered by the computer). lsusb shows "foostan Corne". /var/log/syslog shows nothing out of the ordinary.

When I remove the code for combos, the keyboard works just fine (this keyboard is my daily driver, I've been using it for almost two years without a hitch, on multiple systems).

Code before combos: https://github.com/t-e-r-m/keyboard-keymap-QMK/commit/c694bedae4b6ba1838d75eb0cba155cbc590a01e

Code after combos: https://github.com/t-e-r-m/keyboard-keymap-QMK/commit/0d9e74abc11f1d24d09aad2be08f0749e43bddf1

I can't figure out what the issue is. Although the above example uses just one method for combos, I've tried all the methods described on the documentation page, and they all make the keyboard unresponsive. I also experimented with multiple values of COMBO_COUNT. Everything else works without a hitch.

After enabling combos, I can't reset the keyboard via the predefined reset keys either -- I have to use the hardware button.

Keyboard Used

crkbd

Link to product page (if applicable)

No response

Operating System

Debian Stable

qmk doctor Output

$ qmk doctor
Ψ QMK Doctor is checking your environment.
Ψ CLI version: 1.1.1
Ψ QMK home: /home/user/git/qmk_firmware
Ψ Detected Linux.
Ψ Git branch: master
Ψ Repo version: 0.19.4
⚠ The official repository does not seem to be configured as git remote "upstream".
Ψ All dependencies are installed.
Ψ Found arm-none-eabi-gcc version 8.3.1
Ψ Found avr-gcc version 5.4.0
Ψ Found avrdude version 6.3-20171130
Ψ Found dfu-util version 0.9
Ψ Found dfu-programmer version 0.6.1
Ψ Submodules are up to date.
Ψ Submodule status:
Ψ - lib/chibios: 2022-09-18 10:01:17 +0000 --  (0e9d558b5)
Ψ - lib/chibios-contrib: 2022-10-03 18:09:41 +0200 --  (bb8356fb)
Ψ - lib/googletest: 2021-06-11 06:37:43 -0700 --  (e2239ee6)
Ψ - lib/lufa: 2022-08-26 12:09:55 +1000 --  (549b97320)
Ψ - lib/pico-sdk: 2022-09-19 18:02:44 +0200 --  (8d56ea3)
Ψ - lib/printf: 2022-06-29 23:59:58 +0300 --  (c2e3b4e)
Ψ - lib/vusb: 2022-06-13 09:18:17 +1000 --  (819dbc1)
Ψ QMK is ready to go, but minor problems were found

Is AutoHotKey / Karabiner installed

• AutoHotKey (Windows)
• Karabiner (macOS)

Other keyboard-related software installed

xmodmap

Additional Context

Size before:
   text	   data	    bss	    dec	    hex	filename
      0	  22898	      0	  22898	   5972	crkbd_rev1_custom.hex

Copying crkbd_rev1_custom.hex to qmk_firmware folder                                                [OK]
Checking file size of crkbd_rev1_custom.hex                                                         [OK]
 * The firmware size is fine - 22898/28672 (79%, 5774 bytes free)

After Combos:

Linking: .build/crkbd_rev1_custom.elf                                                               [OK]
Creating load file for flashing: .build/crkbd_rev1_custom.hex                                       [OK]
Copying crkbd_rev1_custom.hex to qmk_firmware folder                                                [OK]
Checking file size of crkbd_rev1_custom.hex                                                         [OK]
 * The firmware size is fine - 24692/28672 (86%, 3980 bytes free)