I performed test connection to one of OPC UA servers using 3-party tool - I don't have any problems. But using PI Connector I've been reciveing still error in log and obviously inability to connect to.
Timestamp: 10/24/2019 21:44:47.148
Message: [ELO] Connection failed. Please verify that the connector trusts the certificate provided by the server. Error: BadCertificateUntrusted Message: Certificate is not trusted. SubjectName=CN=Quickstart DataAccess Server, C=US, S=Arizona, O=OPC Foundation, DC=vxxxxxx2opc Thumbprint=B05B10C7B85DD0B6xxxxxxxxxDD08D033B78CAA6
!!!!! I remembered to move cert file from rejected\certs to trusted\certs folder and restart connector (accordingly with manual). Also I investigated App.OpcUa.Config changing <storetype> from Directory to Windows ...