I have installed all available Arch Linux packages. My system is thus up to date. Since the last update, all mails in the folder list are displayed as unread, even though they are already marked as read in the mail overview. Also a manual change as unread and read again does not help. The mails remain unread in the folder list. Access via IMAP. The database is PostgreSQL.
Created attachment 114522 [details] Version
I just had the same thing happen to me. KMail had been running fine for a couple of days, but suddenly started counting all mails as unread in the folder list and in the taskbar. This is on a Gentoo Linux system, running KDE apps 19.08.2, KDE frameworks 5.63.0, and Qt 5.13.2, fetching mail through IMAP from a Dovecot server to a PostgreSQL 11.5 database.
Having this issue for quite some time. Used to work around it by using: akonadictl fsck while KMail is running and then restarting KMail afterward. But even this doesn't work anymore. It is really annoying and makes KMail unusable. KMail 19.08.3 KDE Frameworks 5.64.0 Qt 5.12.5 PostgreSQL 10.9
This issue no longer exists