IndexOf doesn't return a valid result

[PJanovsky]

Apple platform

iOS

Framework version

net9.0-*

Affected platform version

.NET 9.0.100

Description

In the project targetting the framework net9.0-ios, IndexOf method doesn't work properly on strings in other cultures than "en" when the string is not found.

Note: It works properly in the Console application build for net9.0

Steps to Reproduce

This code returns "4" but "-1" is expected:
return "test".IndexOf("x", "test".Length)

Sample sln is attached.

iOSApp1.zip

Did you find any workaround?

StringComparison.Ordinal must be explicitly used for IndeOf method.

Relevant log output

No response

[rolfbjarne]

This looks very much like dotnet/runtime#111340, so closing as a duplicate of that issue.