Undefined variable: dest_matches via ajax

Calling \FreePBX::Destinations()->destinationUsageArray($dest) from the url config.php does not produce any error.
But when calling it from ajax.php the following error occurs. This error occurs when the destination is not being used.
As seen in the following log, ID 30 is being used in a destination and the error is not generated. But in ID 33 it is not being used and instead of returning the empty array the error occurs.

Example debug config.php

OUT > [2022-09-13 17:31:35] [dbug.DEBUG]: 2022-Sep-13 17:31:35        /usr/src/freepbx/queueprio/Queueprio.class.php:548
OUT > [2022-09-13 17:31:35] [dbug.DEBUG]: ID: 30
OUT > [2022-09-13 17:31:35] [dbug.DEBUG]: 2022-Sep-13 17:31:35        /usr/src/freepbx/queueprio/Queueprio.class.php:549
OUT > [2022-09-13 17:31:35] [dbug.DEBUG]: Array
(
    [text] =>  Used as Destination by 1 Object
    [tooltip] => Queue Priority: Prueba2<br />
)

OUT > [2022-09-13 17:31:35] [dbug.DEBUG]: 2022-Sep-13 17:31:35  /usr/src/freepbx/queueprio/Queueprio.class.php:548f
OUT > [2022-09-13 17:31:35] [dbug.DEBUG]: ID: 33
OUT > [2022-09-13 17:31:35] [dbug.DEBUG]: 2022-Sep-13 17:31:35        /usr/src/freepbx/queueprio/Queueprio.class.php:549
OUT > [2022-09-13 17:31:35] [dbug.DEBUG]: Array
(
)

Example debug ajax.php

OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: 2022-Sep-13 17:30:47  /usr/src/freepbx/queueprio/Queueprio.class.php:548
OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: ID: 30
OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: 2022-Sep-13 17:30:47        /usr/src/freepbx/queueprio/Queueprio.class.php:549
OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: Array
(
    [text] =>  Used as Destination by 1 Object
    [tooltip] => Queue Priority: Prueba2<br />
)

OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: 2022-Sep-13 17:30:47  /usr/src/freepbx/queueprio/Queueprio.class.php:548
OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: ID: 33
OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: 2022-Sep-13 17:30:47        /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Destinations.class.php:209
OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: Undefined variable: dest_matches
OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: 2022-Sep-13 17:30:47  /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Destinations.class.php:210
OUT > [2022-09-13 17:30:47] [dbug.DEBUG]: #0 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Destinations.class.php(97): Whoops\Run->handleError()
#1 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Destinations.class.php(248): FreePBX\Destinations->getAllInUseDestinations()
#2 /usr/src/freepbx/queueprio/Queueprio.class.php(549): FreePBX\Destinations->destinationUsageArray()
#3 /usr/src/freepbx/queueprio/Queueprio.class.php(671): FreePBX\modules\Queueprio->getPriority()
#4 [internal function]: FreePBX\modules\Queueprio->destinations_getdestinfo()
#5 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Hooks.class.php(319): call_user_func_array()
#6 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Hooks.class.php(373): FreePBX\Hooks->executeCall()
#7 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Destinations.class.php(483): FreePBX\Hooks->processHooksByModule()
#8 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Destinations.class.php(226): FreePBX\Destinations->getModuleDestinationInfo()
#9 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Destinations.class.php(201): FreePBX\Destinations->getDestinationInfoByModule()
#10 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Destinations.class.php(125): FreePBX\Destinations->getDestinationsByModule()
#11 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Destinations.class.php(45): FreePBX\Destinations->getPopoversByModule()
#12 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/View.class.php(730): FreePBX\Destinations->getAll()
#13 /usr/src/freepbx/framework/amp_conf/htdocs/admin/helpers/freepbx_helpers.php(109): FreePBX\View->destinationDrawSelect()
#14 /usr/src/freepbx/queueprio/Queueprio.class.php(234): drawselects()
#15 /usr/src/freepbx/framework/amp_conf/htdocs/admin/libraries/BMO/Ajax.class.php(134): FreePBX\modules\Queueprio->ajaxHandler()
#16 /usr/src/freepbx/framework/amp_conf/htdocs/admin/ajax.php(63): FreePBX\Ajax->doRequest()
#17 {main}