20210127 Leader disappeared during big group ride - Network OK

Any idea?
My leader-avatar disappeared during our Zwift Riders Germany Group-Ride on Wednesday evening (at approx. 6:56pm CET, >730 riders) after approx. 56 minutes and did not come back. From my point of view everything looked ok, I still saw everyone, my leader-baecon was there and was able to follow the chat - but nobody could see me and the beacon anymore. I was able to send chat-messages but nobody received them. I had a look in my log-files and did not find anything related, except:

[18:56:28] NETCLIENT:[WARN] TCP connection timed out owing to inactivity [18:56:28] NETCLIENT:[INFO] TCP host
[18:56:28] NETCLIENT:[INFO] Connecting to TCP server…
[18:56:28] NETCLIENT:[INFO] Saying hello to TCP server (largest wa is 1611770153505290)

Client is a Win10 PC, current Zwift-client Game Version: 1.0.61590

Any help appreciated…