App Review says we're using Non Public APIs, although we don't

Hi All, Our app update got rejected with the following reason:

ITMS-90338: Non-public API usage - The app references non-public symbols in GPS: _CCCryptorGCMOneshotEncrypt. If method names in your source code match the private Apple APIs listed above, altering your method names will help prevent this app from being flagged in future submissions....

This is just a regular app update, we didn't do any big changes and we don't use this function or anything related to CommonCrypto/Cryptography in the app. We tried to submit a Code Level Support request but always receive a Gateway Timeout.

Has anyone came across a similiar experience and would be able to help?

App Review says we're using Non Public APIs, although we don't
 
 
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