iOS iPhone 11 flashing black and white while browsler is constantly reloading: RBS Background assertion ConnectionTerminationWatchdog

Question

I get a black & white flashing browser, which is constantly reloading after this error:

[ProcessSuspension] 0x1063b4740 - ProcessAssertion: Failed to acquire RBS Background assertion 'ConnectionTerminationWatchdog' for process because PID is invalid
[Process] 0x104028a18 - [pageProxyID=11, webPageID=12, PID=3734] WebPageProxy::processDidTerminate: (pid 3734), reason 3
[assertion] Error acquiring assertion: <Error Domain=RBSAssertionErrorDomain Code=3 "Target is not running or required target entitlement is missing" UserInfo={RBSAssertionAttribute=<RBSDomainAttribute| domain:"com.apple.webkit" name:"Background" sourceEnvironment:"(null)">, NSLocalizedFailureReason=Target is not running or required target entitlement is missing}>

The issue occurs only with iPhone 11 PRO and iPhone 11 Mini (real devices) and a cordova app on iOS 14.3, 14.4 and 14.5. On emulator it works perfectly and on other real devices as well.

In my case the screen is flashing black and white if I open a dc-Tableview.js table (by adding and removing "diplay:none").

Related issues:

• WKWebView is trying to run on background, although it's closed and should be disposed
• https://github.com/apache/cordova-ios/issues/1103
• https://forum.ionicframework.com/t/ios-background-issue/206463
• https://developer.apple.com/forums/thread/677916?login=true&page=1#674912022
• https://github.com/apache/cordova-plugin-wkwebview-engine/issues/55

System:

• Cordova 10.0.0
• Cordova-ios 6.2.0
• iPhone 11 PRO / iPhone 11 Mini (it is woring on several other devices f.e. iPhone SE, also working on iPhone 11 PRO emulator)
• iOS 14.5

Any thoughts how to fix this?

Answer 1

It seems to occure when the screen is scrolled:

• manually
• by using functions like: scrollintoview()
• with multiple full-size modals used with overflow-y: auto css in modal div container

Edit: Finally, I could solve my issue by hiding all inactive modals in the background by using:

• display: none

Removing the modals, removes the error.

Resizing the modals, removes the error (f.e. height to 30%).

When I delete all my scrollintoview() occurances I only get the flashing bug when scrolling manually.

Hope this helps. Still I don't know how to solve that entirely.

I opened a ticket at apple support: https://feedbackassistant.apple.com/feedback/9363100