timeout when restore key backup

I've just installed riotx but I've been using riot for quite some time already.

In riotx, I see a "Never lose encrypted messages. Use key backup" message. When clicking on the link, I get a "restore from backup" button. When clicking on the button, I get a message asking me to wait while "fetching backup version...". This takes a few tens of seconds and then an error message appears:

> Sorry an error occured: failed to get latest restore keys version (java.net.SocketTimeoutException: timeout)

I'm using riotx 157295240, F-b1171, downloaded from f-droid repo by Krombel, riotx-dev-fdroid.