[Bug] Unexpected RGBLIGHT_SLEEP behavior on split board

Describe the Bug

I've enabled RGBLIGHT_SLEEP in my config.h. When my PC goes to sleep, the secondary half of my board will sleep for maybe 500ms then turn back on. The OLED display will sleep again after some time, but the RGB will not sleep afterwards. Primary half sleeps without issue. My config.h,keymap.c, and rules.mk, can be found in my repo, here.

Keyboard Used

Lily58/rev1

Link to product page (if applicable)

No response

Operating System

Win11

qmk doctor Output

Ψ QMK Doctor is checking your environment.
Ψ CLI version: 1.1.8
Ψ QMK home: C:/Users/Ritvik/qmk_firmware
Ψ Detected Windows 11 (10.0.26100).
Ψ QMK MSYS version: 1.11.0
Ψ Userspace enabled: False
Ψ Git branch: master
Ψ Repo version: 0.29.12
⚠ Git has unstashed/uncommitted changes.
Ψ - Latest master: 2025-08-03 04:01:13 +0100 (ae07dee941) -- Improve 'new-keymap' error handling when default keymap is missing (#25536)
Ψ - Latest upstream/master: 2025-08-06 21:15:03 +0100 (1a58fce043) -- Bump actions/download-artifact from 4 to 5 (#25545)
Ψ - Latest upstream/develop: None
Ψ - Common ancestor with upstream/master: 2025-08-03 04:01:13 +0100 (ae07dee941) -- Improve 'new-keymap' error handling when default keymap is missing (#25536)
Ψ - Common ancestor with upstream/develop: None
Ψ All dependencies are installed.
Ψ Found arm-none-eabi-gcc version 13.3.0
Ψ Successfully compiled using arm-none-eabi-gcc
Ψ Successfully tested arm-none-eabi-binutils using arm-none-eabi-size
Ψ Found avr-gcc version 15.1.0
Ψ Successfully compiled using avr-gcc
Ψ Successfully tested avr-binutils using avr-size
Ψ Found avrdude version 8.0-2025011
Ψ Found dfu-programmer version 1.1.0
Ψ Found dfu-util version 0.11
Ψ Submodules are up to date.
Ψ Submodule status:
Ψ - lib/chibios: 2025-05-15 08:25:11 +0000 --  (8bd61b8043)
Ψ - lib/chibios-contrib: 2025-01-08 21:03:31 +0100 --  (3ac181e4)
Ψ - lib/googletest: 2021-06-11 06:37:43 -0700 --  (e2239ee6)
Ψ - lib/lufa: 2022-08-26 12:09:55 +1000 --  (549b97320)
Ψ - lib/vusb: 2022-06-13 09:18:17 +1000 --  (819dbc1)
Ψ - lib/printf: 2022-06-29 23:59:58 +0300 --  (c2e3b4e)
Ψ - lib/pico-sdk: 2025-04-20 21:24:29 +1000 --  (d0c5cac)
Ψ - lib/lvgl: 2022-04-11 04:44:53 -0600 --  (e19410f8)
Ψ QMK is ready to go, but minor problems were found

Is AutoHotKey / Karabiner installed

• AutoHotKey (Windows)
• Karabiner (macOS)

Other keyboard-related software installed

No response

Additional Context

For some context, I bought a prebuilt Lily58 with rgb underglow but it came with a via compatible Sofle RGB firmware, which was weird but ultimately I had no issue using it. Decided to start cracking on a proper firmware. I saw #22269 which is the same issue except the fix has since been merged. May or may not be related, but enabling RGBLIGHT_SPLIT {20,20} breaks the secondary half of my board as well. Not sure why. Any help is appreciated.