After reconfiguring your monitors, some newly opened applications (for example, QTerminal) won't be managed by fluxbox (no borders, always on top, can't be moved or resized, and don't respect sloppy focus). The bug was fixed in Fluxbox ages ago, but unfortunately there hasn't been a release since then. Let's patch it locally.
TrueOS Edge (based on FreeBSD 12)
Lumina Desktop Environment
Steps to reproduce:
1) Start Fluxbox
2) Open a QTerminal
3) Power off the monitor, or connect an external one
4) Wait 5 seconds
5) Power on the monitor, or remove the external one
6) Start a new QTerminal
The new QTerminal will be outside of fluxbox's control, as described. Only restarting Fluxbox will fix the problem.
Created attachment 192829 [details]
Apply upstream patch for PR 227792
x11-wm/fluxbox: apply upstream patch for bugs 1058, 1102, 1111, and 1140
A commit references this bug:
Date: Thu May 10 20:02:34 UTC 2018
New revision: 469574
x11-wm/fluxbox: x11-wm/fluxbox: apply upstream patch for multiple bugs
Fixes upstream bugs 1058, 1102, 1111, and 1140. Fluxbox hasn't made a
release for 3 years, so we should stop waiting and patch our ports tree.
Approved by: maintainer timeout (jgh)