Downloading multiple files gets stuck on "Wait a moment...": `IndexedForest$Node.getParent()' on a null object reference`

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[X] This is a bug, not a question or an enhancement.
[X] I've searched for similar issues and didn't find a duplicate.
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Steps to reproduce

Select multiple files that have not been downloaded yet
Tap the "Download" option

Expected behaviour

"Wait a moment..." dialog doesn't get stuck

Actual behaviour

"Wait a moment..." remains on screen forever even after all the downloads are complete, making the app unusable until it's manually closed and restarted

Android version

Device brand and model

Google Pixel 7

Stock or custom OS?

Stock

Nextcloud android app version

3.29.2

Nextcloud server version

28.0.9

Using a reverse proxy?

Yes

Android logs

09-22 14:37:16.671 12066 12118 E FileDownloadWorker: Error caught at FilesDownloadWorker(): Attempt to invoke virtual method 'com.owncloud.android.files.services.IndexedForest$Node com.owncloud.android.files.services.IndexedForest$Node.getParent()' on a null object reference
09-22 14:37:16.672 12066 12094 I WM-WorkerWrapper: Worker result FAILURE for Work [ id=ab45576c-80fa-4229-a7ce-62ea6cafa60f, tags={ com.nextcloud.client.jobs.download.FileDownloadWorker, *, name:files_download bakugo@[censored], timestamp:1727012226537, class:FileDownloadWorker, user:bakugo@[censored], folder_downloadbakugo@[censored]3170 } ]
09-22 14:37:16.676 12066 12066 I WM-SystemFgDispatcher: Stopping foreground service
09-22 14:37:17.485 12066 14952 D ContentObserverWork: File-sync Content Observer detected files change
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper: Work [ id=47cce63c-403f-4091-bc60-163c5b4ccbe9, tags={ com.nextcloud.client.jobs.ContentObserverWork, *, name:content_observer, timestamp:1727011205864, class:ContentObserverWork } ] was cancelled
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper: java.util.concurrent.CancellationException: Task was cancelled.
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper:  at androidx.work.impl.utils.futures.AbstractFuture.cancellationExceptionWithCause(AbstractFuture.java:1183)
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper:  at androidx.work.impl.utils.futures.AbstractFuture.getDoneValue(AbstractFuture.java:513)
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper:  at androidx.work.impl.utils.futures.AbstractFuture.get(AbstractFuture.java:474)
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper:  at androidx.work.impl.WorkerWrapper$2.run(WorkerWrapper.java:316)
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper:  at androidx.work.impl.utils.SerialExecutorImpl$Task.run(SerialExecutorImpl.java:96)
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper:  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper:  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
09-22 14:37:17.540 12066 12084 I WM-WorkerWrapper:  at java.lang.Thread.run(Thread.java:1012)

Server error logs

No response

Additional information