SUMMARY
Laptop with two external monitors. If laptop lid is closed, laptop display is not active. System suspends. System is resumed by opening the laptop lid. The greeter is displayed, but it gets the screen configuration wrong. Login on the laptop display is fine, but instead of the a login display being shown on the other two screens one each, there is one login screen shared by both external monitors, with the password entry dialog split. 

The laptop is a full HD display. One external monitor is 4K  (in native resolution, not scaled) and the second is 1920x1200

After logging in, the display configuration is refreshed and there are no problems. 

STEPS TO REPRODUCE
1. Close laptop lid, so that only the two external displays are used.
2. Allow the system to suspend 
3. Resume by opening the laptop display

OBSERVED RESULT
Instead of each of the three screens getting a perfectly sized login screen, the two external monitors share a badly sized login screen split across both.

EXPECTED RESULT
The display configuration should be refreshed before showing the login screens. Then, each of the three monitors would get a well-formed login screen.


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Operating System: KDE neon 5.15
KDE Plasma Version: 5.15.5
KDE Frameworks Version: 5.58.0
Qt Version: 5.12.0
Kernel Version: 5.0.0-16-generic
OS Type: 64-bit
Processors: 8 × Intel® Core™ i7-8550U CPU @ 1.80GHz
Memory: 31.2 GiB of RAM