PC is invisible to SMB client apps on same LAN subnet (Xfinity XB6 gateway)

In case my implicit question needs to be more explicit, here it is: Has anyone gotten Windows' folder-sharing feature to work within the Xfinity gateway's LAN?

... PC is connected to gateway via ethernet. Cellphones connect to gateway via wifi. ...

Does https://forums.xfinity.com/conversations/xfinity-app/turning-off-ap-isolation-also-known-as-client-isolation/61fc4125e5fd17166fe4a59e help?

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@BruceW:  Turniing off the gateway's Xfinity Hotspot service (using the Xfinity app) was one of the first things I did after the gateway was initially activated.  However, I'm not convinced the hotspot actually turned off, because "Xfinity Hotspot" and "xfinitywifi" are displayed in the cellphones' list of available wifi connections when the gateway is on, and aren't listed when the gateway is unplugged from power.  Although I'm tempted to say I tried your proposed solution and it didn't work, I can't be certain it wouldn't solve the folder-sharing problem if the hotspot actually turned off.

   I should add that the proposed solution doesn't make sense to me.  My cellphones connect to the gateway's private wifi SSID, not to the public "Xfinity Hotspot."  And the PC & cellphones are on the same LAN subnet.

   I've dug a deeper hole since I posted the comment (so I should post a brand new comment about that).  As a workaround to try to get folder-sharing to work, I decided to set the Xfinity gateway to Bridge Mode and connected an old TPlink wifi/router to one of the gateway's two ethernet ports. (The other port unused.)  Unfortunately, the TPlink didn't connect to the gateway's internet, so it offered only LAN, no WAN. (If the TPlink's WAN settings need to be configured, I don't know what Xfinity values should be entered into it.)  I then tried to disable Bridge Mode by trying to follow Xfinity's instructions, which say to use the Admin Tool (via a web browser on the PC connected by ethernet).  But the gateway didn't respond at the 192.168.1.1 IP address I'd set it to, nor at the default 10.0.0.1 address. (The web browser timed out.)  The only remaining option was to "factory reset" the gateway, which restored my internet service (using the gateway without the TPlink) and reset the gateway router to 10.0.0.1.  But even though Admin Tool is enabled in the Xfinity app, I can't access the gateway's Admin Tool pages: when I try to login, it says the username or password are incorrect. (The username should still be "admin" because I never found a way to change it.  For the password, I tried both the default password "password" and the customized password I'd set before the factory reset.)

   The Xfinity Assistant bot has been useless for both folder-sharing and the admin password.  And it wouldn't connect me with a human.

Try the default password that is written on a label on the back or the bottom of the device.

@EG: You wrote "Try the default password that is written on a label on the back or the bottom of the device." 

The only password written on the Xfinity XB6 gateway is the default wifi password.  Since my cellphones have no problem connecting to the gateway via wifi, I assume the problem you're trying to help me with is the "incorrect username or password" error when I try to login to the gateway router's Admin Tool service.  When I initially installed & set up the gateway, I had to google the Admin Tool service's default IP address, username & password, because they're not written on the gateway.  The default values are the same for everybody: 10.0.0.1, "admin" and "password".

When I tried logging into the Admin Tool using the default username and password ("admin" and "password"), I got the "incorrect username or password" error. (I also got that error when I tried "admin" and the password that I'd customized before the factory reset.)

Is there any reason to hope that a second factory reset would clear up the "incorrect username or password" Admin Tool login problem? 

I've seen several posts here lately indicating that they recently made a firmware change that now uses the password on the label instead of the usual "password". Not sure if that was pushed to all devices yet. YMMV...

You could give another factory reset a shot. Make sure you hold the button in for 30 seconds. Good luck !

@EG: The default wifi pass-key DOES work for Admin login. (Even though I'd changed the wifi pass-key so its default value should no longer allow wifi access).  I guess this confirms the reports of the recent firmware update.  Thanks for that tip!

Do you have any information about what else the firmware update has changed or added? (I can report that it didn't fix the SMB problem -- Windows shared folder doesn't work within the LAN -- that I asked about initially.)

I see no way to change the Admin password, so it appears to be stuck on the default wifi password. (At least it's not stuck at "password.")  I didn't find an option to change it in the Xfinity app (yesterday), and Comcast cripples the admin access when a gateway is activated. (When I click on Advanced in the Admin Tool pages, it just displays "Managing your home network settings is now easier than ever. Please download the Xfinity xFi app to set up port forwards, among many other features and settings.")

It's clearly not "easier than ever" to manage a network setting that was available in the gateway before it became crippled, but which isn't available in the Xfinity app.  For example, MAC filtering (to restrict wifi access to a whitelist).  For another example, changing the Admin login password. (Unless the Admin login password change option becomes available in the app, the firmware update may have created a new security risk.)

@EG: You wrote: "This is another change that the newer firmware has: