does the same happen on the notebook's internal panel? Fedora uses much more recent kernels and graphics stacks than Fedora. Also GRUB2 is a much newer build. I'd suggest checking on bugzilla for similar reported problems. If there's nothing there, file one.
They'll need at minimum the following:
Notebook specification including details about the GPU(s), UEFI firmware version, monitor and connection used to output to it. specific version number of grub installed (check via dnf if not sure).