Alt key not recognized on system

[spags-lacework]

Describe the bug
Alt key not translating to system. I've loaded https://keyboardchecker.com/ on my system and typed alt which does not get recognized on the system.

System Description

PRETTY_NAME="Ubuntu 22.04.4 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.4 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy

Linux main 6.5.0-1017-aws #17~22.04.2-Ubuntu SMP Mon Mar 25 20:28:54 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

KasmVNC Details

Xvnc KasmVNC 1.2.0.2af2e661e9906b5778644f6e2fbe1f51cebb337a - built Sep 13 2023 23:49:36
Copyright (C) 1999-2018 KasmVNC Team and many others (see README.me)
See http://kasmweb.com for information on KasmVNC.
Underlying X server release 12008000, The X.Org Foundation

To Reproduce
Steps to reproduce the behavior (for non-installation issues):

1. Go to KasmVNC to the System
2. Open up keyboard checker
3. Click alt key
4. Key does not get recognized

Expected behavior
Alt key is recognized.

Browser
If this is a problem with the KasmVNC client, provide details about the browser you are accessing KasmVNC from.

• Device: Macbook pro
• OS: 14.4.1
• Browser: chrome
• Version: Version 124.0.6367.62 (Official Build) (arm64)

** Additional Context **
Keyboard checker doesn't detect alt/super key, but the super key is forwarded while alt is not.

[spags-lacework]

Can I get a response on this please? KasmVNC has worked out wonderfully but this is a weird one that I would expect to just work.