Same problem. Windows 7 64bit + Opera 57.0.3098.91, Nokia 5 + Android 8.1.0 + Opera Touch 1.12.3 (latest versions at the time of posting). Belgrade, Serbia, connecting through Orion Telekom (https://oriontelekom.rs).
Initially when I open the "My Flow" tab it flickers, constantly refreshing its content. When I manage to "catch" the "Connect" button and get the QR code then scan that code using Opera Touch on my phone, I get the "failed to connect" error message. Entering the code manually didn't help either.