Enable imap_debug and check the log.
Hi Alec, i have activated imap_debug in config.php. My installation is in front an imapproxy service and i cant find in imap.log file nothing pointing to query quota
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] Connecting to localhost:xxxx...
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] S: * OK [CAPABILITY IMAP4rev1 LOGIN-REFERRALS ID ENABLE LITERAL+ XIMAPPROXY] Dovecot ready.
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] C: A0001 ID ("name" "Roundcube" "version" "1.4.1" "php" "7.3.11-1~deb10u1" "os" "Linux" "command" "/?_task=mail&_caps=pdf%3D0%2Cflash%3D1%2Ctiff%3D0%2Cwebp%3D1&_uid=4&_mbox=Sent&_framed=1&_action=preview" "x-originating-ip" "XXX.XXX.XXX.XXX")
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] S: A0001 OK Completed
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] C: A0002 CAPABILITY
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] S: * CAPABILITY IMAP4rev1 LOGIN-REFERRALS ID ENABLE LITERAL+ XIMAPPROXY
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] S: A0002 OK Completed
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] C: A0003 LOGIN ****** [40]
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] S: * OK [XPROXYREUSE] IMAP connection reused by imapproxy
[06-Dec-2019 11:36:27 +0100]: <thgcf6g3> [E17C] S: A0003 OK User logged in
this is an excerpt from log.
This config is like this since 5 years.
What could be wrong?