qmk/qmk_firmware

Modifier keys LCTL, LSFT etc. not working under windows remote desktop

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#25979 opened on Jan 27, 2026

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help wantedquestion

Description

Issue Description

Hi, in my keymap I use e.g. LCTL(KC_V) and LSFT(KC_MINS) which work fine under Windows. However, when using Remote Desktop, the modifiers are no longer recognized, i.e. LCTL(KC_V) outputs KC_V only etc.

I assume that Remote Desktop requires some additional delay between pressing LCTL and KC_V.

I tried

void oneshot_mods_changed_user(uint8_t mods) {
	send_keyboard_report();
}

but without success.

Is there any other way?

Contributor guide

Tech stack
c
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
C programmingQMK firmware basicsHID protocol knowledge
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Investigate the QMK key processing pipeline for modifier keys, focusing on files like `quantum/process keycode/process mods.c` and `tmk core/common/keyboard.c`. The issue suggests that Remote Desktop requires a delay between pressing LCTL and KC V. Examine how modifiers are sent in the HID report and consider adding a configurable delay option. Test with varying delay values to find a reliable fix. Also check if there are any existing pull requests or discussions about Remote Desktop compatibility.