MemberExpression is marked as Convert(...) call instead of MemberExpression

I'm currently facing an issue with using Reflection on custom types. I have a method with the following signature:

protected static bool ReplacePropertyValue<TTargetResource, TValue>(TEntity entity, TResourcePatch resourcePatch, Expression<Func<TResource, TTargetResource>> sourceResourcePropertyExpression, Expression<Func<TTargetResource, TValue>> sourcePropertyExpression, Expression<Func<TEntity, TValue>> targetPropertyExpression)

where TEntity is the database-entity I want to update. where TTargetResource is the resource of the patch-document I want the new value from. where TValue is the type of the property I want the new value from to be set in the entity.

resourcePatch contains all the patch-instructions I want to apply to the entity. sourceResourcePropertyExpression is the expression for the resource with the new/changed value. sourcePropertyExpression is the expression to the resource's property with the new/changed value. targetPropertyExpression is the expression pointing to the property which should have the new/changed value.

However I am facing an issue where the targetPropertyExpression is not a MemberExpression. Below is the call of the method

 ReplacePropertyValue(theEntity, resourcePatch, team => team.ParentTeam, pt => pt.Id, team => team.TeamParentTeamId)

However, the last param is shown as {team => Convert(team.TeamParentTeamId)} and I don't get the point why. TeamParentTeamId is of type Guid. When used with another property of type Guid? it works as expected.

Can anyone tell me why the first one (Guid) is a Convert(...)-expression?