When connected with a Guacamole RDP session, the keysym for Caps Lock (0xffe5) is sent over RDP as scancode 0xe03a. Windows does not understand this scancode, thus does not generate the correct VK (Virtual Key) events. Removing +ext from the keymap sends the scancode 0x003a, which is correctly recognized by Windows as Caps Lock. This enables Windows applications to listen for key down and key up events on the Caps Lock key while connected via a Guacamole RDP session.
Note: this issue likely went un-noticed for a long time because it only impacts the key up and down events for the Caps Lock key, not Caps Lock's effect on sending uppercase [A-Z] characters.
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