cached files are causing users to be logged out, or at least appear so

I have found that while I am logged in and opening many pages of the site, when the Autoptimise cache is fairly full then many of the pages I open on the front end show as if I am not logged in – ie User name in header is replaced with “login”, wishlist & compare icons show as empty, and for admin the admin bar at top is gone. If I then navigate from this logged out page to a page that is not yet cached (I assume), then it shows me as logged in again without having to actually log back in.

I found that deleting the Autoptimise cache fixes the problem – temporarily. It doesn’t need to be anywhere near full for this issue to occur.

I believe what is happening is that pages get cached as for someone viewing not logged in & nothing in waitlist, cart, etc. Then if you go to that page, you get the cached version so it looks like you are not logged in and all your user info is not visible.

So it’s impairing functionality of my website. This doesn’t just affect logged in users either. I tested it not logged in. After adding items to my wishlist and compare list I clicked on links to view those lists. For both it showed cached version of page with nothing in list. F5 doesn’t fix this, only deleting the cache by admin