Logical Replication slot disappeared after promote Standby

Hi Community,

I have installed postgres version 17.5 with following setup,

*Primary *
-- Secondary A
-- Secondary B
-- Secondary C

*Config:*
wal_level = 'logical'
max_wal_senders = '10'
max_replication_slots = '10'
wal_keep_size = '512MB'
hot_standby = 'on'
sync_replication_slots = 'on'
hot_standby_feedback = 'on'
synchronized_standby_slots = 'Kafka_logical_slot'

1. slotsync worker is running all the time ( Automatic sync)
2. When I create logical replication slot(Kafka_logical_slot) in Primary,
it got synced on both Secondary A and Secondary B
3. It didn't appear in Secondary C , Since its not direct replica.

*Issue : *
When I stop Primary node and promote one of the Direct secondary (A,B)
node. logical replication slot is vanished.

Am I missing any configuration ?

Please share your experience.

Thanks,