I am having the same issue.
There is a new div element with class q-focus-helper in q-item. The q-focus-helper has opacity and background as currentColor thats causing the issue.
If I may add: your fast response is VERY helpful, as it helps your users not wasting time in such topics. And I don’t take this for granted. With your replies to my - misplaced - reports you saved me some hours today. And I’m sure others feel alike.