Dell XPS 15 Bluetooth lag on startup...

As soon as I got the laptop I went to the Dell website and updated all the drivers using their utility.  I specifically remember that Bios was one of the updates because I had to do that one manually.  I believe that all my drivers and bios are updated at this point.  

Thank you for that suggestion.  I have already installed all the updates and everything seems like it installed correctly.  I don't see any error messages.    

Happy to hear other ideas of how this could be fixed.  I bought the laptop refurbished directly from Dell so perhaps it's an issue with the wireless card? Do you think this is something I should call Dell support about?

You type fast....yes indeed ! :emotion-2:

You install the driver for the Dell Premier Wireless Keyboard and Mouse KM717? If no, click Drivers & Downloads in the link below:

Support for Dell Premier Wireless Keyboard and Mouse KM717 ...

:emotion-2:

I'd suggest you check and see if the latest windows updates are installed on system.  Type Settings onto search box, click Update & Security, and then "Check For Updates". Also check Update History for any failed windows updates. If there are updates, please don't wait later to install, click on "Restart Now ".

If all the latest windows updates are installed and the problem still occur, I suggest you update System Setup (BIOS) on the system. Please click on link below to safety install latest version.

Update System Setup (BIOS) for a Dell Computer ... - …

After updating latest BIOS version, I suggest updating Chipset, Network and some of the other drivers in correct order.

How to reinstall drivers in the correct order | Dell US

Everything works great when I use the Dell dongle - that's not the issue.  The problem I'm having is when I use the bluetooth connection for the keyboard/mouse.  When using bluetooth is when the lag happens on startup/wake.  

RSB1_Boston,

When using the RF 2.4Ghz connection, you have to use the dongle that comes with the keyboard or mouse.
Notes: ◦Make sure the receiver has the Dell Universal symbol Dell Universal Symbol on it.
◦The receiver is not compatible with Bluetooth Bluetooth or Logitech’s Unifying Logitech_Symbol devices.
◦The Bluetooth on the keyboard and mouse uses a Low Energy (BLE), which only works with Bluetooth devices using the chipset/module 4.0 and above on the computer, also it works best with Windows Operating System 8.0 and above.
◦The wireless keyboard and mouse range is 30 feet (10m) maximum, however the wireless strength can be affected by weak batterie's, any other wireless devices nearby, placement of dongle in computer, etc.

Common Wireless Failures and Recommendation

Mouse or Keyboard not responding

The Dell WK717 and WM527 should automatically work with the computer when set to the RF 2.4Ghz connection Selection Option RF. When the mouse or keyboard fails to work, it could be due to one the follow reasons;
•Battery ◦Weak batteries.
Recommended solution: Install new batteries.

•Wrong orientation of batteries.
Recommended solution: Check batteries orientation.
•Make sure the keyboard or mouse power button is set to ON.
•Wrong selection of wireless mode made on the keyboard or mouse.
Recommended solution: Check and select the correct wireless connection mode on the keyboard or mouse.
Notes: ◦Select Selection Option RF on the keyboard/mouse if you are using the dongle. Resynchronize with Dell Universal Pairing if needed. For more information refer to Dell Knowledge Base article How to use the Dell Universal Pairing.
◦Select Selection Option BT1or Selection Option BT2 for Bluetooth pairing. Remember which Bluetooth are paired with the system. Selecting the wrong Bluetooth will lead to either keyboard or mouse not functioning. Re-pair the devices, when needed. For more information refer to Dell Knowledge Base article Fix, Connect to and Learn About Bluetooth.

•Wireless ◦Dongle placement.
Recommended solution: Reinsert the dongle at the front or side of the system. This is because the system would have shield up and reduce the wireless strength.
◦Bluetooth compatibility.
Recommended solution: Check system Bluetooth version and OS version. Keyboard and mouse are having Bluetooth Low Energy (BLE) which will not work on Bluetooth chipset/module 4.0 or below on the system/computer. For compatibility of Bluetooth list, please refer to individual product (KM717, WK717 or WM527). It also works best on Windows OS 8.0 and above.

Note: Sometimes a non-working mouse or keyboard can be caused by other factors like a bad USB port or a bad system Bluetooth chipset or a program crash that could cause the system to hang-up and freezes the keyboard and mouse.Reinstall the computers chipset drivers.

Lastly,

If you updated drivers and check Power Management in device manger, and the problem still occurred, try each step and see if it will a difference.

*Type Troubleshoot onto [Cortana] search box, View All, and then run Hardware & Devices troubleshooter. Run Keyboard and Bluetooth troubleshooters as well.

* Perform a clean boot. Please click link below:

How to perform a clean boot in Windows - support.microsoft.com

Thanks for your continued suggestions.  I believe all the drivers and updates are installed and there's nothing further to update on this front.  I even ran diagnostics on the Dell website and everything came out OK with the laptop.

I went to the Device Manager and I don't see the "Power Management" tab under Keyboard Device or under the Mouse Device.  Having said that, I did go to the Qualcomm Bluetooth Adapter and the Killer Wireless Card device properties and unchecked the "Allow the computer to turn off device to save power" option.  I'm not in my office at the moment so can't check if this worked or not.