This is working as designed. The old legacy S3 is no longer supported. All newer Dell Laptops support Modern Standby S0 sleep only. The BIOS is written with this mandate in mind.
Hi,   I have a G15 5511 laptop with Debian installed. Bios version - 1.16.0 My issue is resembles the one described in [URL] There is no "deep" entry in my "/sys/power/mem_sleep" file. As in the above mentioned link, I am suffering from rapidly discharging battery during the suspend state, as the laptop enters merely to a "s2idle" state. The "Block Suspend" BIOS feature is turned off. Does my device support the deep sleep mode?
G15 5511 Suspend to RAM