It sounds like you updated the email address for your FBX account but not your billing account. Please email us at [email protected] and let us know both the old and new email addresses so we can check for those.
Next time it happens, please use the Send a problem report option on the Support tab to send us your log files so we can check those.
The usual cause of 1s recordings is that the recording PC does not have enough system resources available when FBX tries to start recording so it is forced to immediately stop. The only other reasosn why recording should stop is that you are either out of disk space / have the option to stop recording when disk space is low enabled or you tab away from a fullscreen game.
FBX is a game recorder so recording websites is not really its intended use. However, you can do it by selecting Fullscreen capture mode in the Capture section of FBX's setting, which will then simply record your whole screen.
The size of the file will also depend on the video encoder that is used and the content of the video itself (50mins of a visual novel game would be much smaller than 50mins of an first person shooter, for example).
1.6 - 2.2 GB for a 50 minute recording is actually quite small and definitely at the low end in terms of what you should expect. But 26 - 28 GB is much bigger than anything we're seeing. As a rough guide, when we record for that length of time at 1080p, 60 fps, we tend to get anything from 5 - 15 GB depending on the game.
All we can suggest is to use the Send a Problem Report option on the Support tab to send us a report next time you get a huge file and we can check the log files to see if there is anything unusual going on.