When I lock my system and keep it running and then turn off both monitors using
their power button, then later login. My second monitor will wake up for a
little while and then go back to sleep or display a complete black screed,
after I turned both monitors on with their power button.

Dragging the mouse into the the 2nd monitor doesn't wake it up. I need to turn
the monitor off and then back on. Following this, keep the mouse cursor in the
same monitor and move it around for several seconds for it not go back to sleep
when mouse focus is in the other monitor.

The 2nd monitor model: HP L2445m

$ uname -a
Linux source 6.8.7-1-default #1 SMP PREEMPT_DYNAMIC Thu Apr 18 07:12:38 UTC
2024 (5c0cf23) x86_64 x86_64 x86_64 GNU/Linux

Operating System: openSUSE Tumbleweed 20240423
KDE Plasma Version: 6.0.4
KDE Frameworks Version: 6.1.0
Qt Version: 6.7.0
Kernel Version: 6.8.7-1-default (64-bit)
Graphics Platform: X11
Processors: 24 × AMD Ryzen 9 5900X 12-Core Processor
Memory: 62.7 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 3080/PCIe/SSE2
Manufacturer: Micro-Star International Co., Ltd.
Product Name: MS-7A38
System Version: 8.0