Why Do I Get Charged for a Grindr In-App Feature That Fails to Activate

Grindr, a gay dating app, has a new 'Boost' feature. Subscribers can pay a one-time $14.99 fee to boost their profile for two hours. I often boost my profile by double-pressing the side button, which says, 'Purchase successful. You're all set.' However, the Boost does not happen. It can take 3, 7, or more tries for the Boost to take place. However, Apple charged me for all the failed Boosts. I have gone to the Apple store and have called their customer service, but no one seems to know why that's happening. I've contacted Grindr and been told that it's an Apple issue. I have read posts from other people with this issue on Reddit and have encountered people on Grindr with the same complaint. I have deleted my app multiple times and redownloaded it but to no avail. Does anyone know why this happens?

Thank You!