Sending file with spaces in name only works when launching DeskApp

[nanathlor]

openSUSE versions 15.0, 15.1 and 15.2
DeskApp clients 2.5.4 and 2.6.2 (from https://download.kopano.io/community/deskapp%3A/)

KDE Desktop

In systems settings -Applications-Email Client tried:
kopano-deskapp_mailto.desktop
kopano-deskapp.desktop

Checked settings in ./config/mimeapps.list is correct

From Dolphin - Share - Send As Email
OR
From LibreOffice File-Send-Email Document (or as PDF)

If the filename has NO spaces in it then Kopano DeskApp sends the email correctly
If the filename has space in it the Kopano DeskApp sends the email correctly IF DeskApp is NOT already open.

If the DeskApp is open and I send a file with spaces in then the subject is missing all words after the space and there is no attachment.

e.g. Send File “This is a file.txt” Subject is “This” and there is no attachment
Send File “ThisIsAFile.txt” email sends correctly.

As an aside, mailto does not work at all unless you install gnome-control-center (just install it)

Any ideas?