Exim not all emails coming through

one client is having some issues with some providers like booking.com
hes not getting any emails from them and getting the following error
TLS error on connection from mailout-202-r6.booking.com [37.10.30.7] (SSL_accept): ret 5
i added the following to exim.conf hoping to get more results from log file to understand what exactly is the issue
log_selector =
+tls_certificate_verified
+tls_cipher
+tls_peerdn
+tls_sni
but error is still the same, i checked all dns records + tls on mail server and all is correct, this issue is only happening with like 1-4 emails such as booking.com
any advice how to solve this ?