Windows Desktop App Disconnecting

[S_Bryant]

Hi,

I've been battling with an issue with the Windows Desktop App for the last few months and having tried everything I can from other forum posts and days of testing, I still haven't managed to resolve it.

For the last 7 years, we've been running Yealink T48 series phones alongside the Android & Apple Apps without any issue. We're now starting to transition away from desk phones so I've been testing the web client and the desktop app using Yealink WH66 headsets. The web client/app is working. but we have an issue where the Desktop App comes up as Disconnected. Waiting for Network. The only way to get it to reconnect is to exit the Desktop App and relaunch.




While the app is in a disconnected state, the following behaviour occcurs:

- Direct call to extension running the Desktop App is possible, but it doesn't ring therefore you can't answer it
- Calls to a ring group the extension with the Desktop App is possible and the extension rings, but you can't answer it. When someone else answers the call, the extension occasionally continues to ring
- Call out of the extensions aren't possible until you exit and re-open the client.
- The panel/status don't update

It's strange to me that this issue is only happening on one app, everything other client else works. It is happening on multiple laptops running a mix of Windows 10 and Windows 11. The most frustrating thing is that I've been unable to replicate it on my own laptop, the Desktop App works perfectly for me!

We have another strange and potentially related issue where we intermittantly can't access the management (https://xxx.3cx.com.au:5001/#/login) or web client (https://xxx.3cx.com.au:5001/webclient) interfaces unless in private/incognito mode. It's a bit of a 50/50 if it works or not. If we're in private mode, it works every time though. I thought this could be a DNS issue, but I've double checked our local DNS server (runs on Windows Server 2019) and can't see anything there.

I'm hoping someone might have an idea of where else the issue might be or what testing I could do to narrow it down further.

Thanks!

• 3CX Version 18.0 (Build 418)
• Desktop App Version 18.10.461
• Server OS Windows 10 VM running on ESXI
• Is the 3CX Server Hosted and where? On-Premise
• Has the Firewall Checker passed: YES

 

[SteveITS]

Define "can't access" the web site? What does the browser show?

A disconnection means it loses network connection. It could be temporary and recover. How often does this happen? If often, can you ping the server continually and see if there is packet loss at that time?

 

[S_Bryant]

The desktop app disconnected randomly after a few minutes for a reason I can't identify and then never reconnects. Whereas I can have the Web App running on the same machine working perfectly. At no point do I lose ping to the 3CX Server on that machine and the web app never disconnects.

It seems to be an issue specific to the Desktop App, others appear to be having the same problem, eg. here and here.






In regards to the portal issue, it appears to be unrelated, but I intermittently get a Page Not Found error when trying to access the management portal. However I can always access it when I'm in private mode. It's not a gamechanger, but potentially related.

 

[SweetAction]

My guess would be something on the machine, like an AV or something else that is messing with the network traffic in some way.

The way I would validate this is to (take a backup, pull the drive, whatever) load a new OS on the same physical machine - just blank vanilla Windows, nothing else, not even domain joined, and validate if the issue still occurs. You could even load a Virtual machine on the same hardware and test in there.

If the issue still occurs, it's network side (not machine side) but I'll bet it doesn't. Once you know that it's something on the machine you can start adding the items back to the machine 1 by 1 to discover what does it. I'm betting some AV/management/filtering tool OR some wacky vendor driver / package (Dell's Killer WiFi package causes all sorts of issues as an example).

 

[S_Bryant]

The machine I was testing was a freshly reset copy of Win 11 so there was nothing on there except 3CX and MS365. You might be onto something with the Dell drivers though as we run their hardware. I'll check out the wifi driver and see if that's the culprit, thanks!

 

[SteveITS]

error when trying to access the management portal. However I can always access it when I'm in private mode

I was wondering about that. Have you tried deleting cache/cookies in your browser? Or tried a different browser? All private mode really does is start without a cache or cookies. (also, fun fact: all private windows are actually the same session so not private from each other)

 

[S_Bryant]

The Dell lead was a good one, thanks SweetAction. We run mostly Dell Latitude 5420's and the issue seems to be isolated to them. I've done further testing with an Intel NUC and a Latitude 7420 and they're both working as expected. The Dell 7420 did have the issue at first but was solved by disabling (and subsequent removal of), the Dell Optimizer application.

I still haven't found a solution for the 5420's, BIOS and driver updates haven't worked, so might be a case of waiting for the next updates. There's a fair few posts on the Dell forums about network issues on this series.

Thanks again for the ideas and assistance!

 

[SweetAction]

Happy to help. I've run into these types of issues before and also nailed it down to Dell's drivers/application/utilities setup - my "cheap" workaround was to grab a USB WiFi / Ethernet adapter from Startech or similar and then replace the Dell if I couldn't work around the issue long term.