Can't get DB::raw query to work within the select method of another query

Background

I have a project that manages the finances of certain clients, in the app, I have a Loan, Account, and LoanStatus models in relationship such that Account hasMany loans and a LoanStatus belongsTo a Loan

Account Schema

Schema::create('accounts', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->unsignedBigInteger('user_id'); # as registrant
            $table->string('account_number', 9)->unique(); #AC2347521
            $table->string('firstname', 50);
            $table->string('lastname', 50);
	     ...
            $table->softDeletes();
            $table->timestamps();
            $table->engine = 'InnoDB';

Loan Schema

        Schema::create('loans', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('loan_account_id', 9)->unique(); #LN2347521
            $table->unsignedBigInteger('user_id');
            $table->bigInteger('account_id')->unsigned();
            $table->bigInteger('amount')->unsigned();
            $table->bigInteger('amount_with_interest')->unsigned();
            $table->smallInteger('interest');
            $table->smallInteger('loan_tenure'); #weeks
            $table->dateTime('expiry_date');
            $table->enum('repayment_frequency', ['daily', 'weekly', 'monthly']);
            $table->bigInteger('amount_per_repayment');
            $table->enum('ledger_side', ['credit', 'debit'])->default('debit');
            $table->string('loan_record_token', 50)->unique();
            $table->enum('times', ['first', 'subsequent']);
            $table->boolean('disbursed')->default(false);
            $table->boolean('completed')->default(false);
            $table->softDeletes();
            $table->timestamps();
            $table->engine = 'InnoDB';

Loan Status Schema

Schema::create('loan_statuses', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->unsignedBigInteger('account_id');
            $table->unsignedBigInteger('loan_id');
            $table->unsignedBigInteger('loan_amount');
            $table->unsignedBigInteger('total_paid')->default(0);
            $table->softDeletes();
            $table->timestamps();

Can anyone tell me why the query below returns an empty result set when the last line is present DB::raw("(loan_statuses.loan_amount - loan_statuses.total_paid) AS amount_remaining")

Loan::join('accounts', 'loans.account_id', '=', 'accounts.id')
                ->join('loan_statuses', 'loans.id', '=', 'loan_statuses.loan_id')
                ->whereDate('loans.created_at', '>=', Carbon::parse($fromDate))
                ->whereDate('loans.created_at', '<=', Carbon::parse($toDate))
                ->select([
                    'loans.id',
                    'loans.loan_account_id',
                    'loans.amount',
                    'loans.interest',
                    'loans.completed',
                    'loans.expiry_date',
                    'loans.amount_with_interest',
                    DB::raw('loans.created_at as loan_created_at'),
                    'accounts.account_number',
                    'accounts.lastname',
                    'accounts.firstname',
                    DB::raw("CONCAT(accounts.lastname,' ',accounts.firstname) AS fullname"),
                    'loan_statuses.total_paid',
                    DB::raw("(loan_statuses.loan_amount - loan_statuses.total_paid) AS amount_remaining")
                ]);

please note that the database already has data and only the last column amount_remaining makes the query empty. I also have that exact column query on a different query with no problem