EF6 allow read but disable insert/update/delete during transaction

Question

I am doing some "sync" between different platform. During this sync I try to add/update/remove records. For it I'm wrapping all functionality in TransactionScope

using (var tx = new TransactionScope(TransactionScopeOption.Required,
                       new TransactionOptions
                       {
                           IsolationLevel = IsolationLevel.Serializable
                       },
                       TransactionScopeAsyncFlowOption.Enabled)) { //logic }

But while transaction is alive and user go to website, requests wait untill transaction is commited or rollbacked. I want to omit this and allow user to see data.

I read that for this case I can do SELECT and it will allow requests to read data from db. As I'm working on sync only with 2 entities, I thought it will be enough to select only for this 2 entities. But it doesn't working. Is there any other ways?

using (var tx = new TransactionScope(TransactionScopeOption.Required,
                           new TransactionOptions
                           {
                               IsolationLevel = IsolationLevel.Serializable
                           },
                           TransactionScopeAsyncFlowOption.Enabled)) 
   { 
        _repositoryForEntity1.AsQueryable().LoadAsync();
        _repositoryForEntity2.AsQueryable().LoadAsync();

        // Add/Update/Delete logic

        uow.SaveChanges();
   }