I solved this problem recently.
Broken layout under GNU screen was caused by non-english locale setting.
I changed locale from ko_KR.UTF-8 to en_US.UTF-8 and all works fine. (locales was set via Personal setting of armbian-config)
I hope you developers could reproduce its layout problem by changing locale to ko_KR.UTF-8. (or I think there may be similar problems with some other locales except english)
How to reproduce the prolems.
(Ver 10 burster armbian/NanoPi R2S)
1. Set system locale to non-english. (i.e. ko_KR.UTF-8)
2. Make sure that all of LANGUAGE, LC_MESSAGES, LANG was changed to ko_KR.UTF-8 in /etc/default/locale
3. Reboot or Reconnect ssh
4. Launch GNU screen
5. Launch armbian-config
6. Layout will be broken
