3432550 - SAP Cloud Connector issue: "Unable to connect SAP BAS to on-premise S4HANA via the Cloud Connector"

The BAS (Business Application Studio) is integrated with S4HANA via the cloud connector. When a request is triggered from BAS, the following error appears in BAS: -

Info: Platform: linux
Info: Development environment: Business Application Studio
Info: Business Application Studio Dev space: Full Stack Cloud Application
Info: Cloud CLI tools: 8.7.4
Info: Application Wizard: 1.13.2
Info: SAP Fiori tools - Fiori generator: 1.12.2

Debug Request to URL: failed with message: Request failed with status code 503. Complete error object: { "message": "Request failed with status code 503", "name": "xxxError", "stack": "AxiosError: Request failed with status code 503\n\tat settle (/managed-content/vscode/unzipped/4__sap-ux-rel___sap-ux-application-modeler-extension@1.0.10369/extension/dist/extension-min.js:1647:1184)\n\tat IncomingMessage.handleStreamEnd (/managed-content/vscode/unzipped/4__sap-ux-rel___sap-ux-application-modeler-extension@1.0.10369/extension/dist/extension-min.js:1648:9305)\n\tat IncomingMessage.emit (node:events:526:35)\n\tat endReadableNT (node:internal/streams/readable:1359:12)\n\tat process.processTicksAndRejections (node:internal/process/task_queues:82:21)", "config": { "baseURL": "https://xxxx_xxx.dest/sap/opu/odata/IWFND/CATALOGSERVICE;v=2", "params": { "saml2": "disabled", "$format": "json" }, "httpsAgent": { "_events": {}, "_eventsCount": 2, "defaultPort": 443, "protocol": "https:", "options": { "rejectUnauthorized": true, "noDelay": true, "path": null }, "requests": {}, "sockets": {}, "freeSockets": {}, "keepAliveMsecs": 1000, "keepAlive": false, "maxSockets": null, "maxFreeSockets": 256, "scheduling": "lifo", "maxTotalSockets": null, "totalSocketCount": 0, "maxCachedSessions": 100, "_sessionCache": { "map": {}, "list": [] } }, "headers": { "Accept": "application/json", "cookie": "", "X-Csrf-Token": "Fetch", "User-Agent": "axios/1.6.0", "Accept-Encoding": "gzip, compress, deflate, br" }, "publicUrl": "http://xxx.xxxxxx.xxxx:80", "method": "get", "url": "/" }, "code": "ERR_BAD_RESPONSE", "status": 503 }    Error: Could not query v4 catalog service for xxxx

• Platform: Linux
• Development environment: Business Application Studio
• Dev Space Type: Full Stack Cloud Application
• Cloud connector: 2.15.2 or more

BAS, SCC, 503, CC, Cloud Connector, Tomcat, interface, IP, wrong, misleading, incorrect, Address, SCC IP, subnet, localhost, 8443, browser, local ip, inbound, outbound, handshake timed out, 10000ms, proxy, IP address, region host, Business Application Studio, S4HANA, eu10, 443, firewall, , KBA , BC-MID-SCC , SAP Cloud Connector On-Demand/On-Premise Connectivity , Problem