I don't know if this is related, but there's now a very strange behavior with lost sessions somewhere in the wiki.
https://translatewiki.net/wiki/Thread%3ASupport/TranslateUserManager
You can see strange behavior of "TranslateUserManager" creating log entries with repeated (and public) incorrect statements, which are also privacy breaches for connected users. Internally there was incorrect tries of TranslateUserManager trying to automatically create a user account from my IPv6 address. This could occur when the server looses the session and I need to login again. It may just happen that it failed to get some session cookie, or there may be simultaneous random uses of IPv4 and IPv6 caused by background JSON requests using a different DNS resolver somewhere in the Javascript framework.
But it may also be another related problem of synchronisation between the main server and cache servers. At least this gives a date of start of this issue : 15 August, to be correlated with recent version updates in translatewikinet and incorrect asumptions in servers (like: the same connectd user cannot send requests from BOTH IPv4 and IPv6, or when this happens the incorrect assumption that there's a one-to-one mapping.
I have not specifically chosen IPv4 or IPv6, both may be used in HTTPS, but I note that the server now uses MIXED contents with HTTP and HTTPS, and their routing may be very different. Also this dates seems to coincide to a change in Google Chrome, that wants to enforce the switch from HTTP to HTTPS if this works, even if the requests are initially instructed (in JSON requests or XMLTHttpRequests). I note that my Gogole Chrome constantly displays deprecation warnings.
Be aware that mixed HTTP/HTTPS will soon be banned and are being phased out quite aggressively. And many Javascript frameworks have to be updated (including for example jQuery, but also MediaWiki itself, and requests for all external sites, including Wikimedia commons for files displayed in translatewiki.net in an unrelated domain).
May be this new bug signaled in TWN Support should have its own bug here in Phabricator, in that case move this message to the appropriate place.