Ubuntu 19 problem getting into sleep mode

I hoped by now that installing Ubuntu/linux would be easy by now. But oh what was I wrong.

I have one problem left. My dell xps 15 won't go into sleep mode. I got this error message in dmesg when it return from sleep:

[10631.377010] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[10631.378239] printk: Suspending console(s) (use no_console_suspend to debug)
[10631.378888] wlp59s0: deauthenticating from 80:2a:a8:18:07:93 by local choice (Reason: 3=DEAUTH_LEAVING)
[10631.489677] pci_pm_suspend(): hcd_pci_suspend+0x0/0x30 returns -16
[10631.489687] dpm_run_callback(): pci_pm_suspend+0x0/0x140 returns -16
[10631.489691] PM: Device 0000:00:14.0 failed to suspend async: error -16
[10631.574195] PM: Some devices failed to suspend, or early wake event detected

I searched the internet but I didn't find the right answer yet. Hope to find any help here. Thanks