I can confirm that the solution Florian posted (modifying /lib/udev/rules.d/97-hid2hci.rules) works for me as well.
Dell Latitude E6500, Kubuntu 18.04 with hwe kernel (4.18.0-13-generic), udev/systemd version 237-3ubuntu10.9, bluez version 5.48-0ubuntu3.1
I can confirm that the solution Florian posted (modifying /lib/udev/ rules.d/ 97-hid2hci. rules) works for me as well.
Dell Latitude E6500, Kubuntu 18.04 with hwe kernel (4.18.0- 13-generic) , udev/systemd version 237-3ubuntu10.9, bluez version 5.48-0ubuntu3.1