In OpenSSL 3.0, the EVP_sha256 function and others like (aes256, etc) are deprecated in favor of the new functions EVP_MD_fetch/EVP_CIPHER_fetch.

MongoDB should call EVP_MD_fetch/EVP_CIPHER_fetch once at startup (like on Windows) when compiled against OpenSSl 3.0. If MongoDB does not call these functions, these are instead called by OpenSSL on each call to EVP_DigestInit_ex which is wasteful. The lookup is time consuming enough to show up on performance tests in MongoDB code which are crypto sensitive.

Reference:
https://www.openssl.org/docs/man3.0/man7/crypto.html