Well that`s not reassuring. 
Maybe I should start considering manual data retrieval? If it is an option.
Both of my installs are made on clean Ubuntu 16.04 VPS following official readme. Both instances are running on psql (PostgreSQL) 9.5.5. That was the first thing I checked. 
At ScaleWay I have chosen Docker kernel. My other install is on DigitalOcean 1GB RAM. As far as I can check everything is up to date.