[Bug]: iOS badge "Increase" not applied (stuck at 1) despite OneSignal showing "Increment by 1"

[twelve-cgn]

What happened?

Description:

I am using the OneSignal .NET SDK in a .NET MAUI app targeting iOS.

I am trying to use badge increment functionality, but the badge count is not behaving as expected.

What OneSignal shows in dashboard/logs:

"Badges: Increment by 1"

So it seems OneSignal correctly recognizes the request.

Actual behavior on device:

Badge is set to 1
Sending multiple notifications (without opening the app) does not increase the badge
It always stays at 1

Environment:

.NET MAUI (net10.0-ios)
OneSignal .NET SDK 6.1.4
iOS device (not simulator)
App is not opened between pushes

Additional notes:

I am not using a Notification Service Extension currently
The payload is recognized correctly by OneSignal backend

Question:

Is ios_badgeType = "Increase" expected to work without a Notification Service Extension?

Or is badge incrementing on iOS dependent on:

Notification Service Extension
or server-side badge state management?

Any clarification on how badge increment is actually handled on iOS would be appreciated.

Steps to reproduce?

I send push notifications with:

ios_badgeType = "Increase"
ios_badgeCount = 1

What did you expect to happen?

Badge should increment:
1 → 2 → 3 → ...

Relevant log output

Code of Conduct

• I agree to follow this project's Code of Conduct