[k-9-mail] Notifications not disappearing

If there are some noitifications for new emails and I open k9 using the home app shortcut and not the notification, after I have read the new emails, the notification doesn't disappear. Why? -- You received this message because you are subscribed to the Google Groups "K-9 Mail" group. To

[k-9-mail] K9 has stopped

I keep getting random "K9 has stopped" error messages that they closes the the app. Sometimes it happens several times in a row 15-30 seconds apart. Other times it happens once every few minutes. I've reported it for the last 3 to 4 days but it keeps doing it. I am using a Samsung Galaxy S7