boot failure only on first try when starting computer

[Peter Baranyi <peter.baranyi@gmail.com>]

hi,

when I turn on my desktop computer (i5 Skylake) with Debian testing,
on the first try it always freezes right after the grub menu. Then
when I press reset, it always boots correctly. I have one SATA SSD (/,
/home), one SATA HDD (only storage) and one M2 NVME SSD (not even
mounted, has Windows).

How do I fix this? Thanks!
Peter