I think it might be this. Funnily running powercfg –energy in cmd reported > S1 Sleep Supported false S2 Sleep Supported false S3 Sleep Supported false S4 S

I think it might be this. Funnily running powercfg –energy in cmd reported > S1 Sleep Supported false S2 Sleep Supported false S3 Sleep Supported false S4 Sleep Supported true Which... seems quite wrong given I can put my laptop to sleep lol. But thanks for the pointer, even though I was aware LTT did the video on sleep it'd fallen out of my memory (pun not intended). Edit: I think I partially solved it. Running powercfg /a reveals... The following sleep states are available on this system: Standby (S0 Low Power Idle) Network Connected Hibernate Fast Startup The following sleep states are not available on this system: Standby (S1) The system firmware does not support this standby state. This standby state is disabled when S0 low power idle is supported. Standby (S2) The system firmware does not support this standby state. This standby state is disabled when S0 low power idle is supported. Standby (S3) The system firmware does not support this standby state. This standby state is disabled when S0 low power idle is supported. Hybrid Sleep Standby (S3) is not available. The hypervisor does not support this standby state. (I have hyper V enabled.) So it does look like S0 sleep is the culprit.