SUMMARY
Trying to install rpm packages on OpenSUSE Tumbleweed fails with the error message: "internal error" and the rpm not being installed

STEPS TO REPRODUCE
1. Download RPM file from third party
2. open it using Discover
3. click install

OBSERVED RESULT
The RPM package is not installed, "internal error" occurs

EXPECTED RESULT
Discover installs the RPM file

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
Operating System: openSUSE Tumbleweed 20210119
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2
Kernel Version: 5.10.7-1-default
OS Type: 64-bit
Processors: 8 × Intel® Core™ i7-6700K CPU @ 4.00GHz
Memory: 23.4 GiB of RAM
Graphics Processor: GeForce GTX 1080/PCIe/SSE2

ADDITIONAL INFORMATION
This is the log output of Discover when opening the rpm file and trying to install it:
took really long to fetch PackageKitBackend(0x558be7f0bf10)
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/ItemViewHeader.qml:52:9: Unable to assign QQuickPopupItem to Page_QMLTYPE_121
qrc:/qml/ApplicationPage.qml:357:25: Unable to assign [undefined] to QString
qrc:/qml/ApplicationPage.qml:355:25: Unable to assign [undefined] to bool
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/ActionToolBar.qml:110:18: QML ToolBarLayout: Binding loop detected for property "actions"
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/ActionToolBar.qml:110:18: QML ToolBarLayout: Binding loop detected for property "actions"
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/ActionToolBar.qml:110:18: QML ToolBarLayout: Binding loop detected for property "actions"
percentage cannot be calculated
percentage cannot be calculated
percentage cannot be calculated
file:///usr/lib64/qt5/qml/org/kde/kirigami.2/private/PrivateActionToolButton.qml:71:5: QML Binding: Binding loop detected for property "value"
percentage cannot be calculated
percentage cannot be calculated
percentage cannot be calculated
percentage cannot be calculated
percentage cannot be calculated
percentage cannot be calculated
percentage cannot be calculated
percentage cannot be calculated
percentage cannot be calculated
percentage cannot be calculated
PackageKit error: PackageKit::Transaction::ErrorInternalError "Interner Fehler" "Die Installation wurde gemäß Anweisung abgebrochen."
(translation: ErrorInternalError "Internal Error" "The installation was canceled according to the instructions.")
PackageKit stopped running!