Are you saying that if you restart a new account, then 10-day forecasts come back when logged in? Do new users not see this problem? I endure the ads, but good 10-day forecasts make them worth it.
As long as we're on the topic of 10-day forecasts, it continues to exasperate me (and I have reported this) that in the 10-day plot, the dew point is plotted on a 0-100F scale, meaning that whatever temperatures are plotted with it end up on that scale. So if you display dew point, the whole plot - everything - gets squished vertically. This is just nuts, and can't be hard to fix. My suspicion is that they have a fraction of a person working part time on all this. My "comfort level" depends on dew point, so how it varies is important to me.