Steps to reproduce:

1. Create original page
2. Create variant page with date trait, so page variant is always visible (e.g have date range for current month)
3. Create component inside variant page.
4. Create variant of that component (now you need to use cookie trait to be able to switch display for the component) - e.g set default provided cookie : weatherLocality : Basel
5. Time to reproduce the problem: 
   a) no cookie exists --> variant page is displayed (due to date trait) together with original component of that variant page.
   b) add cookie : weatherLocality: Basel --> variant page is again displayed (due to date trait) and original component of variant page is displayed. Of course from logs it is easy to figure out why this is happening (cache is serving based only on page uuid - there is NO component uuid used on key generation)