
firefox does not delete cookies
Firefox 65.0.1 (64-bit) for Mac (Mojave 10.14.3)
When I clear all cookies (privacy & security -> cookies & site data -> clear data (everything) or history -> clear history -> everything) the storage tab shows that the cookies are gone but they're not. I'm not logged out of Google and any newspapers I've read retain their article access count. I have to clear cookies, quit Firefox and restart it to actually clear cookies. This is a big privacy problem.
This doesn't seem like it should be a problem seventeen years after Firefox was first introduced. How do regressions like this keep happening with every release?