It's definitely a Windows issue. I've had it with non-XPS Dells and completely different brands like Eluktronics.
Didn't notice it in the first couple years of ownership, not sure if it was because my usage patterns changed or some not-so-helpful update that made it worse, but it's really absurd that I can't predict what will happen when I close the laptop.
I did something to disable network activity from interrupting standby, which reduced the issues a bit but not consistently.
https://docs.microsoft.com/en-us/windows-hardware/design/dev...
Intel have just removed S3 sleep from the latest Tigerlake chip so there isn't an alternative.