when you use SubsetRandomSampler it by defaults suffles the dataset so you can’t use shuffle while using it.
train_loader = DataLoader(dataset=hotdog_dataset_train,  batch_size=8)
val_loader = DataLoader(dataset=hotdog_dataset_val, batch_size=8)

Should work.
Or you can directly use following commands and remove previous declarations of hotdog_dataset_train and hotdog_dataset_val
train_loader = DataLoader(dataset=hotdog_dataset,  batch_size=8, sampler = train_sampler)
val_loader = DataLoader(dataset=hotdog_dataset, batch_size=8, sampler = val_sampler)