it was solved when i changed on BIOS the Touchpad option from Advanced to Basic Features.
as the user Keith Brown. When Adding "acpi_osi=" to GRUB_CMDLINE_LINUX_DEFAULT left me without a trackpad.
my device is an Acer Predator Helios 300 | Debian Stretch 9.5.0
it was solved when i changed on BIOS the Touchpad option from Advanced to Basic Features.
as the user Keith Brown. When Adding "acpi_osi=" to GRUB_CMDLINE_ LINUX_DEFAULT left me without a trackpad.
my device is an Acer Predator Helios 300 | Debian Stretch 9.5.0