The IPN response always worked when I tested my transactions on the paypal sandbox. However, it does not work on my live website.
Some more details:
-Using a modified version of MicrojobEngine (modifications made by myself and a web developer. We had absolutely no experience working with wordpress or paypal prior to this project)
-The problem exists using a fresh version of the theme (it initially didn't matter if the IPN response was valid or not)
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