I use a Broadcom bluetooth dongle for my Magic Mouse since the MP's built-in bluetooth is too weak. I'm in the slow process of configuring a clean Mojave install on a NVMe drive to replace my primary Sierra install. This is my work computer, so I do this in my spare time (hence the slow process). And since Sierra does not recognize NVMe, I have to boot from a third drive in High Sierra before I can boot from Mojave on the NVMe drive. To summarize: • Sierra on Apricorn Velocity Duo SSD Raid = current main startup drive • High Sierra on HDD = interim drive to recognize NVMe • Mojave on NVMe SSD = future main startup drive My problem is that whenever I switch startup drive, the mouse becomes unresponsive and I have to play with Bluetooth Explorer and reboot multiple times to get the dongle recognized again, especially when switching from Mojave back to Sierra. I suspect some BT info is updated in NVRAM when I boot in Mojave. Any suggestion on how to smooth this transition?