openssl s_client -connect securepayments.sberbank.ru:443
в половине случаев получаем:
$ openssl s_client -connect securepayments.sberbank.ru:443
CONNECTED(00000003)
write:errno=104
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 338 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)
---
во второй половине - Verify return code: 19 (self-signed certificate in certificate chain), что означает отсутствие корневого сертификата
такое впечатление, что там балансировщик кидает то на хороший сервер, то на плохой