unable copy file to External SDcard in my tablet

Since updating from 13.2 to Leap 42.1, I am having problems copying files from my PC to SDCard in my tablet with Dolphin. It would only allow copying to the internal storage in the tablet ( my tablet has 16GB internal memory and I have added a 32GB SDCard).
I normally connect the Tablet to PC via USB2, open dolphin and split view using the 2nd view to open access to the tablet, in this view the files on the SDCard are listed. when I drag a file across from the PC to the Tablet it fails with ’ Access denied Could not write to.’
I do not have this problem with Konqueror. Is there some configuration missing or set within dolphin which block this action?

Dolphin do now work as well as it use to… Has anyone come across this problem copying file to other devices within Dolphin?

I have same your problem
I using dolphin (root) for copy
Try with dolphin super mode

if that’s an android tablet try kde-connect no need for cables (if you’re on the same wireless network)
if you still want to use a cable, check and see how are you connecting your tablet, some android devices have multiple options, you can switch between usb storage, media device (mtp), camera (ptp), charge and build in cd-rom.
I do believe only usb storage and mtp are accessible via dolphin, also kit-kat has issues writing on external sd cards you might need to do some patching.
I still believe that kde-connect is the best way to transfer files between Linux and Android, you’d need to have it installed in both Linux and Android