Why am I getting larger values as progress value?

I added some logs to the progress value and I am seeing some unusual numbers as progress which breaks my application.

`I/flutter (18984): progress-------------------------------------------------------
I/flutter (18984): 0
I/flutter (18984): progress-------------------------------------------------------
I/flutter (18984): -107600
D/ViewRootImpl@e6138ee[MainActivity](18984): ViewPostIme pointer 0
D/ViewRootImpl@e6138ee[MainActivity](18984): ViewPostIme pointer 1
D/ViewRootImpl@e6138ee[MainActivity](18984): MSG_WINDOW_FOCUS_CHANGED 0
D/skia (18984): --- SkAndroidCodec::NewFromStream returned null
I/flutter (18984): progress-------------------------------------------------------
I/flutter (18984): 2147426496
════════ Exception caught by widgets library ═══════════════════════════════════
The following _Exception was thrown building MovieDownloads(dirty, state: _MovieDownloadsState#37025):
Exception: Percent value must be a double between 0.0 and 1.0
The relevant error-causing widget was
MovieDownloads
lib\widget\download_page.dart:105
When the exception was thrown, this was the stack
#0 new CircularPercentIndicator
package:percent_indicator/circular_percent_indicator.dart:103
#1 _MovieDownloadsState.build.
package:next_hour/widget/movie_downloads.dart:190
#2 MappedListIterable.elementAt (dart:_internal/iterable.dart:415:29)
#3 ListIterable.toList (dart:_internal/iterable.dart:219:19)
#4 _MovieDownloadsState.build
package:next_hour/widget/movie_downloads.dart:238
...
════════════════════════════════════════════════════════════════════════════════
D/ViewRootImpl@e6138ee[MainActivity](18984): MSG_WINDOW_FOCUS_CHANGED 1
D/skia (18984): --- SkAndroidCodec::NewFromStream returned null
I/flutter (18984): progress-------------------------------------------------------
I/flutter (18984): 100
D/DownloadWorker(18984): File downloaded`

As you can see the above logs, the progress is started with a 0, then gets a larger negative value, a larger positive value, and finally ends up with 100.

Why is this happening?