jupp same problem for me Discover is not launching! I managed to get it to open using these commands;
First type this in terminal; pkill discover
Then type this; plasma-discover --backends packagekit-backend
But I get this warning:
Warning: Setting a new default format with a different version or profile after the global shared context is created may cause issues with context sharing.
org.kde.plasma.libdiscover: OdrsReviewsBackend: Fetch ratings: true
adding empty sources model QStandardItemModel(0x561ab3095e30)
qrc:/qt/qml/org/kde/discover/qml/Feedback.qml:4:1: module "org.kde.userfeedback" is not installed
PackageKitBackend: No distro component found for "us.getsol.solus"
qrc:/qt/qml/org/kde/kirigami/private/PrivateActionToolButton.qml:71:5: QML Binding: Binding loop detected for property "value":
qrc:/qt/qml/org/kde/kirigami/private/PrivateActionToolButton.qml:74:9
AppStreamIntegration: No distro component found for "us.getsol.solus"
It opens Discover, but its only temporary