Netconf communication in SDN-R devicemanager was changed to new ODL interfaces (org.opendaylight.mdsal.binding.api.DataBroker). Old interfaces here are Depreciated in ODL Flourine. 

Problem: There is no databroker delivered by the connected mountpoint with interface class "org.opendaylight.mdsal.binding.api.DataBroker" and communicaton with device is not possible.

New interfaces used:
import org.opendaylight.mdsal.binding.api.DataBroker;
import org.opendaylight.mdsal.binding.api.MountPointService;

Working code with old but Depreciated interfaces:

import org.opendaylight.controller.md.sal.binding.api.DataBroker;
import org.opendaylight.controller.md.sal.binding.api.MountPoint;

Code part (old style), is not delivering back the DataBroker for connected device:

Optional<DataBroker> optionalNetconfNodeDatabroker = mountPoint.getService(DataBroker.class);

Analysis:

In ODL Repo for NETCONF related function: https://github.com/opendaylight/netconf/blob/release/nitrogen-sr2/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/sal/NetconfDeviceSalProvider.java

It is visible that ODL code for NETCONF in Flourine SR2, that creates the mountpoint seems not to provide the "new" mdsal interface classes:
 netconf/[netconf|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf]/[sal-netconf-connector|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector]/[src|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src]/[main|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src/main]/[java|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src/main/java]/[org|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src/main/java/org]/[opendaylight|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src/main/java/org/opendaylight]/[netconf|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf]/[sal|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal]/[connect|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect]/[netconf|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf]/[sal|https://github.com/opendaylight/netconf/tree/release/fluorine-sr2/netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/sal]/NetconfDeviceSalProvider.java