SUMMARY
Single file transfers go through correctly, but Multiple file transfers fails, only one file is transferred to android Xiaomi Redmi NOTE 7, from Xubuntu 16.04 64bit.

STEPS TO REPRODUCE
1. Select multiple files to transfer, then right click and select Send To> KDEConnect-send choose Device and click Send.
 
2.Another approach were to make Thunar custom action following this guide https://rafaelc.org/tech/p/send-files-to-your-phone-from-file-manager/ after doing so, files again failed and only one were transferred. '

3. 

System: Lenovo Thinkpad X300

OBSERVED RESULT
Only 1 out of 5 files transferred


EXPECTED RESULT

All 5 files transferred sucessfully

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 5

ADDITIONAL INFORMATION

OS: Ubuntu 16.04.7 LTS x86_64 
Host: 647814G ThinkPad X300 
Kernel: 4.4.0-189-generic 
Uptime: 7 hours, 34 mins 
Packages: 3323 (dpkg), 5 (snap) 
Shell: bash 4.3.48 
Resolution: 1440x900 
DE: Xfce 
WM: Xfwm4 
Theme: BlackCrOrange 
Theme: Greybird [GTK2], Arc-Darker [GTK3] 
Icons: elementary-xfce-darker [GTK2/3] 
Terminal: xfce4-terminal 
Terminal Font: DejaVu Sans Mono 12 
CPU: Intel Core 2 Duo L7100 (2) @ 1.201GHz 
GPU: Intel Mobile GM965/GL960 
Memory: 1881MiB / 3878MiB