Mediator does not register handlers from package assembly

[MarekBalazEset]

Hello,
I tried to replace MediatR by Mediator package in several projects. In my team, we have custom package with standards that contains some handlers. Firstly, I replaced MediatR by Mediator in this package (lets call it Standards.Processors). Then, I updated Azure Function app with Topic triggers. I updated all haldners but I wasn't able to register Mediator as services.AddMediator in Program.cs because I got ambiguous exception. Therefore, I used following approach:
Microsoft.Extensions.DependencyInjection.MediatorDependencyInjectionExtensions.AddMediator(services, o => { o.ServiceLifetime = ServiceLifetime.Scoped; o.Assemblies = [typeof(WorkspaceForwardingHandler<>), Assembly.GetExecutingAssembly()]; });

WorkspaceForwardingHandler is handler in my Standards.Processors package. During running Function App (called PricingProcessor ), I got runtime exception:
Exception: Mediator.MissingMessageHandlerException: No handler registered for message type: Standards.Processors.Mediation.Requests.WorkspaceForwardingRequest1[[PricingProcessor.FunctionApp.Dependencies.Mediation.Requests.GetBillingPriceRequest, PricingProcessor.FunctionApp, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]
`
It looks like Mediator does not consider assemblies in the list. Does any one similar experience?

[martinothamar]

Program.cs because I got ambiguous exception

Are there multiple Mediator.SourceGenerator packagereferences in the project graph here or something? Hard to tell what is wrong from just textual descriptions here, usuall would need a repro to tell what is going on. Another options is to have a look at some of the existing samples to see if you have similar patters or architectures