Same here! Very flustrating (Mac OS 12.5.1).

in my case, I found the cause is the use of ModelContext's batched fetch method: func fetch<T>( _ descriptor: FetchDescriptor<T>, batchSize: Int ) throws -> FetchResultsCollection<T> where T : PersistentModel The cure for my code is replacing this problematic fetch with the plain fetch method: func fetch<T>(_ descriptor: FetchDescriptor<T>) throws -> [T] where T : PersistentModel I am not sure this cure is effective in other cases but I feel the current maturity of the batched fetch is very low and very unstable.