I typically run updates pretty frequently, but didn't install BIOS 2.4.1 for the XPS 9365 (along with other updates) until just recently. Soon after, I noticed that there were boot issues where the Dell logo would appear, but Windows 10 would never start loading. I would then have to hold the power button down long enough to shut down, then power it back on and it would boot.

This morning, I installed the previous BIOS version 2.3.1 and so far, it seems like the boot issue is gone.

So, I think there might be an issue with the 2.4.1 BIOS release.