In the last few firmware updates for Quest somethings have changed with respect to the drivers. I'm not exactly sure of the details but it seems that some drivers are not automatically installed and the device simply will not connect.
You may think that everything is working because your headset will connect as an MTP device ( file explorer ) and it may even have a popup in the headset asking you to allow - don't be fooled this is just the popup to allow access to the file NOT the ADB allow popup. The ADB one has a checkbox for "Always Allow from this PC" and that's how you can tell the difference at a glace. They are otherwise identical.
Below is the full guide to properly installing your Quest drivers on Windows 10. For windows 7 + 8 the instructions are very similar but your mileage may vary.
Ensure that your Oculus Quest is connected to your PC via USB.
Ensure that your Oculus Quest is the only android device connected to your PC.
Ensure that you have followed all the steps here to setup developer mode.
Double check that developer mode is enabled in the Oculus App on your phone.
Search for "Device Manager" in the start menu and click it to open it
Look for a device called "ADB Interface" inside a section called "Other Devices". Right click it and select "Update Driver".
If you don't see "ADB Interface" in the list make sure your headset is connected on a proper working USB cable. If you are sure and have checked all the things here. If you are still having issues at this step then come and chat with us on discord.
A driver install wizard will popup, select "Browse my computer..."
A on the next screen select "Let me pick from a list...".
On the next screen look for "Oculus Device" in the list and select "Next". If you don't see the "Oculus Device" then follow Step 3 here.
On the right side of the next screen be sure to select the third option called "Oculus Composite ADB Interface" and click next.
If you see a warning about installing the driver just click yes.
OK now that you have installed the proper driver, restart everything to give you a clean start - restart your PC, your Headset and then open SideQuest again.
I hope that helps some of you that cant get the headset to connect despite trying everything.
As always if you have any issues please connect with us on Discord.