Standalone uCMDB Browser unable to connect to HA uCMDB server behind loadbalancer


I having issue connecting standalone ucmdb browser 4.14 on Tomcat over HTTPS to uCMDB server. Two node HA uCMDB 10.3x servers located behind loadbalancer. I imported CA certificate chain from LB to JAVA JRE truststore, but  connection fails. LB is BigIP F5 v13

2017-10-25 10:57:31,256  ERROR  [pool-3-thread-1] UcmdbConnectionImpl - Could not connect to UCMDB server for connection: server: ucmd******, customer: N/A
com.hp.ucmdb.api.CommunicationException: Connection to uCMDB server was not successful.

Caused by: com.hp.ucmdb.api.CommunicationException: Connection reset

Caused by: Connection reset


If I bypass loadbalancer and specify connection directly to ucmdb server then all working.

I imported same certificates to UD Probe truststore and connection trough LB working without issues

Also found java code for testing HTTPS connection ( at Troubleshooting in bottom)

If certificates imported to "cafile", then HTTPS connection to ucmdb behind LB succeeds:
/app/jdk1.8.0_151/jre/bin/java Test
HTTP/1.1 200 OK
Date: Thu, 26 Oct 2017 11:09:53 GMT
X-Frame-Options: SAMEORIGIN
Content-Security-Policy: frame-ancestors 'self'
Content-Length: 0
Set-Cookie: BIGipServer~DR~ucmd******_8443_pool=rd100o00000000000000000000********************; path=/; Httponly; Secure

And without certs it looks like this:

/app/jdk1.8.0_151/jre/bin/java Test
Exception in thread "main" PKIX path building failed: unable to find valid certification path to requested target

What else I should check?