Why email app badge doesn't show correct count after iOS 18.2.1 Update

First, I will note that I found this answer in the community posts but it was buried in the solution. I am re-writing and submitting this here with a new question which I hope better describes the original problem.

After the 18.2.1 update I was perplexed that the red badge on the email app showed a 1 or a 5 yet opening the email showed many many more unread messages. What gives? Did a search and found out about the new Categories. Changed that to List View, but this did not fix the problem. Here's why: I have multiple email accounts instead of just one and my email app was set to show all inboxes. In my case the fix is to show all mailboxes then tap each account one at a time to view only that email account and then tap on the three dots in top right and select List View instead of the now default "Categories". Doing this while showing all mail does not apply to all accounts and you have to apply the change individually to each account in your app.