Stacking Apps

I’ve been following some couponers on social media that post deals that require submitting receipts to multiple apps. I recently tried a deal and submitted to Swagbucks, Shopkick and Checkout51. Swagbucks immediately flagged my receipt as a duplicate, saying it had already been submitted. I contacted support and they said it had been flagged as being submitted already to another service. I knew that Swagbucks/InboxDollars/ TaDa/MyPoints were all the same, but I’m curious if this has happened to anyone else? I was unaware that I couldn’t use more than one app, and it seems like many others are doing so. I’m new to couponing, but I think I’ll stick to Ibotta.