The cause is actually likely related to a network configuration problem when you check the HCX logs
/common/logs/admin/app.log
2020-02-25 21:44:12.291 UTC [InterconnectService_SvcThread-11, IX:823808a3-3282-4821-82eb-766e898e7a08, J:fb97eaeb, , TxId: ae31b326-54c6-446d-afbe-6097f548d2f0] INFO c.v.v.h.s.i.AppliancePostConfigJob- WAN-OPT login failed. Requeuing back. Re-try attempt 2
2020-02-25 21:44:16.246 UTC [VsphereReplicationService_SvcThread-329, Ent: HybridityAdmin, , TxId: f2cdb8dc-1be6-45fe-be1d-9135b5f14145] INFO RCM- Cleaning the cache since 5
2020-02-25 21:45:16.259 UTC [VsphereReplicationService_SvcThread-341, Ent: HybridityAdmin, , TxId: f2cdb8dc-1be6-45fe-be1d-9135b5f14145] INFO RCM- Cleaning the cache since 5
2020-02-25 21:45:17.375 UTC [InterconnectService_SvcThread-20, IX:823808a3-3282-4821-82eb-766e898e7a08, J:fb97eaeb, , TxId: ae31b326-54c6-446d-afbe-6097f548d2f0] ERROR c.v.v.h.a.gateway.GatewayAdapter- Exception while posting configuration to gateway.
org.apache.http.conn.ConnectTimeoutException: Connect to 10.2.42.11:9443 [/10.2.42.11] failed: connect timed out
at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:143)