Android K9 window/app will not close

K9 version = 5.600, Unit = Android 6.0, LG V10, AT&T
Ample memory, less than 50% allocated.

K9 works flawlessly with multiple accounts & multiple mail servers; however there is one non-email account exception/anomaly.

Very recently, when I employed the “Clear all” function to close all my windows, K9 appears “stuck “and refuses to close.

Yes, all the other open apps close.

Yes, the “Clear all” function worked on K9, perhaps as late as a week ago.

The K9 app is the outlier.

Due to “Clear all” function, the K9 app window is reduced in size, but touching the [X] in the top right corner of the K9 reduced window has no effect.

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Restart phone = yes, no change
Power off phone = yes, no change.
Force stop K9 app = yes, no change
Performed above evolutions several times.

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When I’m in the K9 app and I want to exit, I can swipe the delta in the lower left corner.

The app disappears.

BUT, if I now invoke “Clear all”, the bugger appears, because it never closes.

Correct, have not seen this behavior before.

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