Apple Mac Client. No Heartbeat. mcs2-cloudstation-eu-central-1.prod.hydra.sophos.com - Server did not respond to client hello - 503 service unavailable

Hi. Our Mac Clients with Intercept-X today getting no Heartbeat. Again. Very frustrating. Need to adjust Firwewall rules that rely on heartbeat every week - weaken them to allow traffic without heartbeat...

The machines display MCS errors.

"invalid server URL"

Thats what our firewall logs

Thats on the EP

While setting up heartbeat with the firewall, they only produce SSL errors.

[2023-11-06 08:54:33.758Z] DEBUG ClientInfo.cpp[25427]:25 ClientInfo - Added new Client Info: c52c0c12-xxxx-xxxx-xxxx-xxxx1c5aa844 172.xxx.xxx.xxx 20676
[2023-11-06 08:54:33.758Z] INFO HBSession.cpp[25427]:504 logNewSession - New Session: [172.xxx.xxx.xxx]:20676 connected
[2023-11-06 08:54:33.758Z] DEBUG HBSession.cpp[25427]:505 logNewSession - EP_Name: CLIENTHOSTNAME EP_ID: c52c0c12-xxxx-xxxx-xxxx-xxxx1c5aa844
[2023-11-06 08:54:33.768Z] WARN HBSession.cpp[25427]:344 bufferDisconnectEvent - Incoming connection from 172.xxx.xxx.xxx failed. SSL error:
[2023-11-06 08:54:33.768Z] DEBUG HBSessionHandler.cpp[25427]:111 markSessionAsDirty - Set session dirty
[2023-11-06 08:54:33.768Z] DEBUG ConnectionWentDownHandler.cpp[25427]:42 handleDisconnect - Endpoint disconnected (172.xxx.xxx.xxx). Sending implicit logout to the access server.
[2023-11-06 08:54:33.768Z] DEBUG Endpoint.cpp[25427]:243 eventCleanUp - eventCleanUp for ep :c52c0c12-xxxx-xxxx-xxxx-xxxx1c5aa844
[2023-11-06 08:54:33.768Z] DEBUG Endpoint.cpp[25427]:269 startHeartbeatLostTimer - HeartbeatLost timer of <285> secs started for EP : c52c0c12-xxxx-xxxx-xxxx-xxxx1c5aa844

any suggestions on permanent fixes?