I have an XPS 13 9300 (bought in 2020). It was so frustrating to spend $2000 on a machine with many issues such as constant freezing (hangs, lockups) and sleep/boot issues. The laptop has never wakened up from sleep and could be stuck in an infinite boot loop (Dell boot logo would never disappear, the caps lock key could blink, and sometimes only a hard reset could resurrect my XPS). It is essential to mention that I have constantly updated all drivers and BIOS, and nothing seemed to work. 

I recently found the solution to such problems! 

1st) I solved the freezing (hangs, lockups) issues by unchecking "Panel Self Refresh" on the Intel Graphics Command Center --> Power Settings --> On Battery

2nd) The sleep/boot issues were solved when I disabled sleep mode in the BIOS configurations. After turning on your computer, press F2 and turn off sleep mode. My laptop now only hibernates instead of sleeping.

That is all, folks! Now, I feel better and relieved. XPS 13 has been my work machine, and it has been slowing me down with such problems. Now it seems things are back on track again!