See steps to reproduce below. Reproducible: Always Steps to Reproduce: 1. Have a USB flash drive connected and detected by system. 2. Click in systray to open the device notifier. 3. Click on a partition on the USB flash drive. Actual Results: No action is done on the first click on the partition. The second click mounts the FS and opens it in Dolphin. Expected Results: FS mounted and opened in Dolphin on the first click on partition in Plasma device notifier. It seems like the first click is wasted on switching focus to the device notifier popup, because when I attach a USB flash drive with two partitions and click once on partition1 and click once again on partition2, then partition2 mounts and opens in Dolphin, while partition1 remains unmounted. The popup focus issue is very similar to bug #348905.
Can't reproduce in: Distribution: KDE neon Developer Edition - Stable Branches Plasma: 5.11.4 Frameworks: 5.41.0 Qt: 5.9.3 Kernel 4.10.0-40-generic
This is fixed anyway in the 5.20 UI overhaul. :)