I am maintaining a PWA that utilizes WebSockets. In this app, after the web page is loaded from the server, JavaScript establishes a WebSocket connection. Because the app connects to a completely local server on a managed local network, we use http:// and ws:// (non-secure). The Issue: The app worked perfectly from older iOS versions up to iPadOS 18. However, during testing on iPadOS 26, we encountered an issue where the WebSocket connects successfully but is disconnected by the iPad approximately one second later. According to our packet captures, the iPad is sending a FIN packet to initiate the teardown. Additional Context: What makes this particularly confusing is that we have another server hosting the exact same PWA where the WebSocket connection stays stable even on iPadOS 26. This suggests it might not be a universal OS bug, but perhaps related to specific network conditions or a new security policy. Has anyone experienced similar behavior on iPadOS 26? Could this be a bug, or is there a new security restriction regarding non-secure WebSocket (ws://) connections in local networks? Are there any known changes in WebKit/Safari for iPadOS 26 that might cause the OS to send a FIN packet immediately after a handshake? I would appreciate any insights or suggestions on what might be causing this.

If the host name included in the URL of the PWA and the host name included in the URL of the xlsx file accessed from within the PWA match, the upper menu portion of the application selection screen for opening the xlsx file will be blank. However, if the host name in the PWA URL is changed from the PC name to an IP address and the host name in the URL of the xlsx file accessed from within the PWA is left as the PC name so that the host names do not match, the upper menu portion of the application selection screen for opening the xlsx file will be displayed. (e.g., the Safari icon appears in the upper right corner). Is anyone else experiencing the same phenomenon? Is it a bug?

The behavior has changed when specifying an xlsx file in the src of iframe in my PWA app. On iPadOS 17.3：Content of xlsx file shown in iframe On iPadOS 17.5.1：A screen appears on top of the original screen to select an app to open the xlsx file. I would like to restore the original behavior, but how can I do that? In addition, if i open and operate the same URL as the one opened in the PWA app in Safari on iPadOS 17.5.1, "download test.xlsx dialog" is open and the dialog has view or download buttons. If the behavior has changed to same to safari on iPadOS17.5.1, it is good for me.