IOS App is slow to connect over cellular

I’m having connection issues with the iOS app. The IOS app connects immediately over WiFi, but takes 11 - 12 seconds to connect using a cellular connection. The black “connecting” message is displayed at the bottom of the screen. Connecting is slow using either myOpenHab.org or using port forwarding.

Once the app is connected it responds as expected.

Also, Siri shortcuts to fail to run over cellular (either in the Shortcuts app or on the watch via a voice command) with a “Sorry, can’t find empty.” message. I’m assuming this is related to the long connection time, but I thought I should mention it.

I do not know if this issue started with the new version of the app, after upgrading to OH5, after upgrading to IOS 26, or any or all of the above.

The legacy version of the app connects immediately over cellular.

I have not been able to find any messages in either openhab.log or events.log. Also could not find any issues in the network & firewall logs.

I’ve verified:

  • All of the programs / apps are the current versions.
  • Other apps running on the NAS preform as expected.

I’ve tried:

  • Deleting / re-installing the app
  • Changing various settings in the iOS app.

I have no idea how to resolve this. Any help is appreciated.

IOS App Version 3.1.42 (99)
iPhone 16 Pro, iOS 26.3
OH 5.1.2 Release build, Main UI Commit 88ebe7ee
OH is running in Docker on a Synology NAS.

openHab application on iPhone - Off-Topic - openHAB Community