ObjCRuntime.ObjCException: Objective-C exception thrown. Name: NSInternalInconsistencyException Reason: Monitor named shinygeofences is already in use

[development-jantar]

When I call StopMonitoring(string identifier), each time with two different 'identifier', I always get the same exception on iOs.
Wierd thing is, I get "Monitor named shinygeofences is already in use" ... but I use different 'identifier' and not 'shinygeofences'.
What I am doing wrong?

ObjCRuntime.ObjCException: Objective-C exception thrown.  Name: NSInternalInconsistencyException Reason: Monitor named shinygeofences is already in use
Native stack trace:
	0   CoreFoundation                      0x00000001a1014970 2F32D384-4637-3018-843E-4FC875B865C4 + 809328
	1   libobjc.A.dylib                     0x000000019def1814 objc_exception_throw + 88
	2   Foundation                          0x000000019ee8fbe8 42C593BB-89FB-3EC4-8220-C746811E7A43 + 9464808
	3   CoreLocation                        0x00000001b99d1504 CLInternalGetPinnedLocationAuthorizationState + 77156
	4   Maui                0x0000000100eb7294 xamarin_dyn_objc_msgSend + 160
	5   Maui                0x000000010107f340 do_icall + 444
	6   Maui                0x000000010107d86c do_icall_wrapper + 348
	7   Maui                0x00000001010773bc mono_interp_exec_method + 6648
	8   Maui                0x00000001010739ec interp_entry_from_trampoline + 640
	9   Maui                0x0000000100e6da60 native_to_interp_trampoline + 112
	10  Maui                0x000000010115805c -[__MonoMac_NSAsyncSynchronizationContextDispatcher xamarinApplySelector] + 96
	11  Foundation                          0x000000019e5c51d0 42C593BB-89FB-3EC4-8220-C746811E7A43 + 246224
	12  CoreFoundation                      0x00000001a0fb7f10 2F32D384-4637-3018-843E-4FC875B865C4 + 429840
	13  CoreFoundation                      0x00000001a0fb7e84 2F32D384-4637-3018-843E-4FC875B865C4 + 429700
	14  CoreFoundation                      0x00000001a0f95b30 2F32D384-4637-3018-843E-4FC875B865C4 + 289584
	15  CoreFoundation                      0x00000001a0f6c6d8 2F32D384-4637-3018-843E-4FC875B865C4 + 120536
	16  CoreFoundation                      0x00000001a0f6ba6c 2F32D384-4637-3018-843E-4FC875B865C4 + 117356
	17  GraphicsServices                    0x00000002458fd498 GSEventRunModal + 120
	18  UIKitCore                           0x00000001a6a1bdf8 C768F963-A0CC-3F5C-A1D3-2E06D53A2381 + 646648
	19  UIKitCore                           0x00000001a69c4e54 UIApplicationMain + 336
	20  Maui                0x0000000100e84618 xamarin_UIApplicationMain + 60
	21  Maui                0x000000010107f1f8 do_icall + 116
	22  Maui                0x000000010107d86c do_icall_wrapper + 348
	23  Maui                0x00000001010773bc mono_interp_exec_method + 6648
	24  Maui                0x0000000101074170 interp_runtime_invoke + 236
	25  Maui                0x00000001010461d0 mono_jit_runtime_invoke + 1256
	26  Maui                0x0000000100ff5374 mono_runtime_invoke_checked + 148
	27  Maui                0x0000000100ffa938 mono_runtime_exec_main_checked + 116
	28  Maui                0x000000010104c538 mono_jit_exec + 352
	29  Maui                0x0000000100eb5dd4 xamarin_main + 2064
	30  Maui                0x00000001010abaec main + 64
	31  dyld                                0x000000019df46e28 8ACDB580-8AB7-38C0-A586-E667ADB1C11C + 20008

   at CoreLocation.CLMonitor.RequestMonitor(CLMonitorConfiguration config, Action`1 completionHandler) in /Users/builder/azdo/_work/4/s/macios/src/build/dotnet/ios/generated-sources/CoreLocation/CLMonitor.g.cs:line 201
   at CoreLocation.CLMonitor.RequestMonitorAsync(CLMonitorConfiguration config) in /Users/builder/azdo/_work/4/s/macios/src/build/dotnet/ios/generated-sources/CoreLocation/CLMonitor.g.cs:line 208
   at Shiny.Locations.GeofenceManager.GetMonitor()
   at Shiny.Locations.GeofenceManager.StopMonitoring(String identifier)

[development-jantar]

I tried to update the Shiny to latest version (beta) and it does help, partially, as I do not get the error "Monitor named shinygeofences is already in use" anymore.

What is also interesting is that calling 'GetMonitorRegions()':

List<GeofenceRegion> geofenceRegions = [.. MauiProgram.GetServiceProvider().GetRequiredService<IGeofenceManager>().GetMonitorRegions()];
if (geofenceRegions is not null && !geofenceRegions.Any(x => x.Identifier == "Arrival")

... give me zero rows, but when calling
await MauiProgram.GetServiceProvider().GetRequiredService<IGeofenceManager>().StartMonitoring(geofenceRegionArrival);

I get
2026-05-05 10:09:37.086 [1 ] ERR [System.Object] Application error: System.InvalidOperationException: A region with the identifier 'Arrival' already exists

... this happens only on iOs, Android works.
This happens with latest preview version (4.1.0-beta-0108).

[aritchie]

Please file a proper bug with a reproducible sample and I'll take a look when I have a chance: https://github.com/shinyorg/shiny/issues

[development-jantar]

#1622