Magento 1.9 catalog price rule issue - 23/04/2018 18:59 EDT - open to bidding

Hey there, I've worked with you in the past on a different account for my other job. Was really satisfied with your work. I have an urgent project for Magento 1.9, and another project in Magento 2.1 Are you able to help? OVERVIEW A client is currently having a reoccuring issue with their online catalog sales. Site URL to be provided once you message saying you can help. DETAILS: Client has a website running Magento ver. 1.9.0.1. Currently when they are applying sales via Magento Catalog Price Rules (Promotions -> Catalog Price Rules), the sales are applying..... but after a small portion of time, an issue occurs: THE ISSUE: After approximately 24-48 hours (unsure on exactly how long), the products seem to appear to remain on sale when browsed via the category pages, but when you click into the product or try to add to cart, the sale doesn't seem to be applied anymore. At this point, if you go back to the rule and hit save and apply, it starts working again. WHAT I KNOW -Settings are all good on the price rules -They are hitting "Save and Apply" when creating or modifying these rules. ---NOTE--- Currently their inventory management team is going in and on the daily re-saving and applying their catalog price rules. Any thoughts on what might be happening? Let me know if you need anything and if you can give me a rough quote. I DO NOT have approval to go ahead and fix this if its going to cost a lot, so please QUOTE me first.