RxApp.MainThreadScheduler seems off since 16.1.1

[jon-peel]

Describe the bug

I don't know if this is a bug, or I am just doing something wrong.
I updated to the latest Nuget (from 14.3.1 to 16.2.1 ReactiveUI, and ReativeUI.XamForms) and I started getting wrong thread exceptions in my UWP project.

I am using RxApp.MainThreadScheduler.
I set a breakpoint, and in the Immediate Window I do a quick System.Threading.Thread.CurrentThread.ManagedThreadId. I expect it to return 3, but it was returning random numbers in the 20s.

I went back to the NuGets, and went down to 14.3.10. I hit the breakpoint, my test returned 3, and the code ran.

I then tried 15.1.1, that worked.
I then tried 16.1.1, that did not work.

It might just be my solution, but RxApp.MainThreadScheduler doesn't seem to be working in the last two versions.

Steps To Reproduce

1. Update an existing Xamarin Forms app (UWP, in case it makes a difference) to ReactiveUI 16.1.1 or 16.2.1.
2. Code relying on RxApp.MainThreadScheduler is running on the wrong thread.

Environment

• OS: Windows 11
• Device: Alienware laptop
• Version: 16.1.1, 16.2.1
• Working Version: 15.1.1

Additional context

I don't know if this is a bug, or it is just a quirk in my project.
It is not critical for me, because 15.1.1 is working fine.
Just FYI, and I am happy to try to answer questions if this looks like it might be a problem, and I am happy to close if it is just me.

[ChrisPulman]

Fixed with #2999
Please update to 16.3.10

[jon-peel]

I updated. Same problem.

Have posted more detail here -> reactiveui/ReactiveUI#2993
It seems to be a more appropriate place for this comment.

[glennawatson]

Feel free to open new issues, old issues are hard to track. Thanks