This solution turned out to be temporary and now does not work. Overnight and without my permission, Windows 11 once again rebooted and installed updates and now the issue started recurring. I uninstalled the updates, but the issue has continued to recur several times per day. If Microsoft does not respond soon with a solution, I will have no recourse but to purchase three new monitors from another manufacturer.
The following isn't a solution, but it has reduced the number of incidents of this horrible issue:: I set my three Philips monitors to NEVER sleep and use a blank screensaver. I don't like doing this as the monitors still put off a faint glow, and I have no idea what this means in terms of power usage, component ware, and power consumption. However, not having this issue surface from sleeping monitor wakeup events helps a little -- Note to Microsoft: This is NOT a solution. Please help.