Postgres BDR replication stopped - replication slot inactive

Our Postgres BDR database system stopped replicating data between the nodes.

When I did a check using the pg_xlog_location_diff I noticed that there is a growing buffer in the replication slot.

SELECT slot_name, database, active, pg_xlog_location_diff(pg_current_xlog_insert_location(), restart_lsn) AS retained_bytes
FROM pg_replication_slots
WHERE plugin = 'bdr';
                slot_name                |   database   | active | retained_bytes
-----------------------------------------+--------------+--------+----------------
 bdr_26702_6275336279642079463_1_20305__ | ourdatabase  | f      |       32253352

I also noticed that the slot is marked as active=false.

SELECT * FROM pg_replication_slots;
-[ RECORD 1 ]+----------------------------------------
slot_name    | bdr_26702_6275336279642079463_1_20305__
plugin       | bdr
slot_type    | logical
datoid       | 26702
database     | ourdatabase
active       | f
xmin         |
catalog_xmin | 8041
restart_lsn  | 0/5F0C6C8

I increased the Postgres logging level, but then only messages I see in the log are:

LOCATION:  LogicalIncreaseRestartDecodingForSlot, logical.c:886
DEBUG:  00000: updated xmin: 1 restart: 0
LOCATION:  LogicalConfirmReceivedLocation, logical.c:958
DEBUG:  00000: failed to increase restart lsn: proposed 0/7DCE6F8, after 0/7DCE6F8, current candidate 0/7DCE6F8, current after 0/7DCE6F8, flushed up to 0/7DCE6F8

Please let me know if you have an idea how I can re-activate the replication slot and allow the replication to resume.