Query: Bulk creation a records issue through flow

Scenario: Whenever Loan (Opportunity) is created, check below conditions and create Amortization schedule records as per the loan tenure value. 

Criteria: Loan Status = Active; Loan Stage = Disbursed; Loan Tenure ISNULL False. 

I have created a flow which create a records as expected. However, there is an obstacle when Amortization schedule is created there is field called Remaining Outstanding amount ( Data Type: Currency ), and Payment_Date__c ( Data Type: Date ) that is not updating as expected. 

Test Data: 

Field: Value

Loan Amount: 4,000,000 

Interest Rate: 13% (Annual) 

Loan Tenure: 12 Months 

EMI Start Date: 3rd April 2025 

EMI Amount (Calculated): 424,218.47 

Expected Output: 

EMI No. | Payment Date | EMI Amount | Interest Paid | Principal Paid | Remaining Principal

1 | 3-Apr-2025 | 424,218.47 | 43,333.33 | 380,885.14 | 3,619,114.86 

2 | 3-May-2025 | 424,218.47 | 39,830.41 | 384,388.06 | 3,234,726.80 

3 | 3-Jun-2025 | 424,218.47 | 35,551.88 | 388,666.59 | 2,846,060.21 

4 | 3-Jul-2025 | 424,218.47 | 30,512.16 | 393,706.31 | 2,452,353.90 

5 | 3-Aug-2025 | 424,218.47 | 24,738.85 | 399,479.62 | 2,052,874.28 

6 | 3-Sep-2025 | 424,218.47 | 18,267.77 | 405,950.70 | 1,646,923.58 

7 | 3-Oct-2025 | 424,218.47 | 11,144.68 | 413,073.79 | 1,233,849.79 

8 | 3-Nov-2025 | 424,218.47 | 3,424.45 | 420,793.02 | 813,056.77 

9 | 3-Dec-2025 | 424,218.47 | 0 | 424,218.47 | 388,838.30 

10 | 3-Jan-2026 | 424,218.47 | 0 | 424,218.47 | -35,380.17 

Current Output: 

Name | Loan__c | Payment_Date__c | Payment_Amount__c | EMI_Amount__c | Principal_Paid__c | Interest_Paid__c | Remaining_Principal__c 

AS-8529523 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

AS-8529524 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

AS-8529525 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

AS-8529526 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

AS-8529527 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

AS-8529528 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

AS-8529529 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

AS-8529530 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

AS-8529531 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

AS-8529532 | 006NS00000S4iS9YAJ | 2025-06-03 | 416684.91 | 416684.91 | 386684.91 | 30000 | 3613315.09 

That's mean, the records data in a salesforce would be as expected output. 

Below are my flow structure for your reference. 

Let me know if more information is required to investigate further.