QT + Android + UI becomes unresponsive when switching apps

When: When switching apps, or after the app resumes from standby. This happens randomly like 1 in 4.

Android platform: Android 10 high probability of other platforms affected as well. App targeting SDK 29/30.

Logs: There's one runtime error reported which does not cause the app to abort and seems to be handled internally by QT.

Other suspicious log fragments are reported as warning to be seen below:

D ZrHung.AppEyeUiProbe: restart watching
D mali_winsys: EGLint new_window_surface(egl_winsys_display *, void *, EGLSurface, EGLConfig, egl_winsys_surface **, EGLBoolean) returns 0x3000
I HwViewRootImpl: removeInvalidNode all the node in jank list is out of time
D mali_winsys: EGLint new_window_surface(egl_winsys_display *, void *, EGLSurface, EGLConfig, egl_winsys_surface **, EGLBoolean) returns 0x3000

I chatty : uid=10249(org.AppXproject.AppXoken) qtMainLoopThrea identical 24 lines

I Camera : open camera: 0, package name: org.AppXproject.AppXoken
D HwFrameworkSecurityPartsFactory: HwFrameworkSecurityPartsFactory in.
I HwFrameworkSecurityPartsFactory: add HwFrameworkSecurityPartsFactory to memory.
I HwCameraUtil: notifySurfaceFlingerCameraStatus : isFront = false , isOpend = true
D SensorManager: 0x7b073b5a30 addFd fd=128

W Gralloc3: allocator 3.x is not supported

D libAppXoken_arm64-v8a.so: needed to resize
D libAppXoken_arm64-v8a.so: size: 0 , new size: 6220800
 *E Surface : dequeueBuffer: IGraphicBufferProducer::requestBuffer failed: -19*
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libEGL : EGLNativeWindowType 0x7b24d7a650 disconnect failed
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W mali_winsys: native_window_api_disconnect failed: -19
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
W libEGL : EGLNativeWindowType 0x7af4b57010 disconnect failed
W libappoken_arm64-v8a.so: QEGLPlatformContext: eglSwapBuffers failed: 300d
D ZrHung.AppEyeUiProbe: not watching, wait.
D ZrHung.AppEyeUiProbe: restart watching