I’m using the iPad Pro 12.9 (2020, Cellular + Wi-Fi, iPadOS 15.0.2, Sold in Mainland China), and it was unable to find the server. I have checked the Local-Networking switch in the Settings and it was on.
I was thinking that the reason caused this problem was the spacedesk App may not supported an iOS Region-Specific feature called “Network Access Permission” yet. (Introduced in iOS 10)
This feature was currently available on the iOS device with Cellular function (both iPhone and iPad) that sold in Mainland China, the non-cellular (Wi-Fi only) version of iPad that sold in Mainland China was not affected by this.
It basically was when the App running for the first time, iOS will showed a prompt pop up to ask user “Allow ‘App’ to use wireless data?” and iOS will block all the network access (including Wi-Fi and Local-Networking) for this App until user allows it from that prompt.
The prompt was controlled directly by iOS and seems like it does not allow developers manually checking it, but if the App only using socket for networking, this prompt will never popup and causing the users was never able to use the App’s networking features. The workaround for that is called some networking API (eg NSURLRequest) to trigger the prompt.
I have test the spacedesk App on my iPhone 12 Pro (iOS 15.2.1, Sold in HongKong SAR, China) and my iPhone XS (iOS 15.2.1, Sold in New Zealand) and those devices was able to find the server without any problems.
After I doing some research I found most of people who cannot use the spacedesk App was running it on the Chinese model of iOS device. (including me..) So I was wondering maybe that was the reason causing the spacedesk App was unable to find any server even the Local-Networking switch was on.
Looking forward for the spacedesk teams to solve this problem.
This is noted, thank you very much for the info. Our developer will check this as soon as he works on iOS viewer again (currently very busy with higher prioritized bug fixes and improvements in Android Viewer).