Performance - POST and PUT for /inventory/items endpoint takes ~10 to ~15 seconds

mod-inventory-storage/items Postgresql DEBUG log:
Attached below.

Workflow to reproduce:
I'm running a pretty straightforward workflow:
1. GET all mod-inventory items
GET /inventory/items
2. GET 200 - Get Material-types
GET /material-types?query=(name=book)
3. GET 200 - Get Loan-types
GET /loan-types?query=(name=can circulate)
4. GET 200 - Get Holdings-storage records
GET /holdings-storage/holdings?LIMIT=1
5. POST new inventory/items
POST /inventory/items
6. GET 200 - /inventory/items using barcode
GET /inventory/items?query=(barcode=${barcode}).
7. PUT 204 - Update mod-inventory/item by doing PUT by ${modInventoryItemId}
PUT /inventory/items/${modInventoryItemId}
8. GET 200 - Get updated mod-inventory/item by using ${modInventoryItemId}
GET /inventory/items/${modInventoryItemId}
9. DELETE 204 - mod-inventory item by modInventoryItemId
DELETE /inventory/items/${modInventoryItemId}
10. Verify mod-inventory item is deleted by doing GET - 404
GET /inventory/items/${modInventoryItemId}

Observation:
POST HTTP request takes ~10 seconds and PUT HTTP request takes ~15 seconds to execute. I have attached logs/screenshots from Postgre SQL, JMeter and Postman.