Since version 0.8.7.2, specifically commit https://git.xfce.org/apps/xfce4-terminal/commit/?id=386e42995d71149d05f232e95d175a853a2f0bf2, I can no longer reliably re-open the dropdown terminal with a hotkey (using xfce hotkey settings and "xfce4-terminal --drop-down" ) unless "keep window open when losing focus" is checked. The previous commit, https://git.xfce.org/apps/xfce4-terminal/commit/?id=634658a628e992e18c20c47244ad725f3c8890b8, does not have this bug and my hotkey works perfectly. Once the dropdown has been opened and closed once, a normal keypress will result in the terminal quickly flashing open and instantly closing. The terminal can sometimes be opened by very quick key taps or quick double taps, but this is unreliable.
*** Bug 14290 has been marked as a duplicate of this bug. ***
Igor referenced this bugreport in commit 2f6db7f83c6db2e12e76ebb4a75ff1bd3eea38cf Fix drop-down terminal hotkey https://git.xfce.org/apps/xfce4-terminal/commit?id=2f6db7f83c6db2e12e76ebb4a75ff1bd3eea38cf
Thank you for the report! That commit has indeed broken the functionality, I've reverted it. Somehow the new APIs do not provide the same result as the deprecated gdk_keyboard_(un)grab().
*** Bug 14301 has been marked as a duplicate of this bug. ***
*** Bug 14303 has been marked as a duplicate of this bug. ***
*** Bug 14304 has been marked as a duplicate of this bug. ***