Zabbix 6.0.21 template import fails

[Raido]

Hi

Stuck with updating existing template with updated items&triggers. Tempate upload fails with Unexpected server error.
Apache2 error log shows following

[Wed Sep 27 07:29:22.394524 2023] [php7:notice] [pid 2573892] [client 194.204.61.131:59097] PHP Notice:  Undefined offset: 249 in /usr/share/zabbix/include/classes/import/CConfigurationImport.php on line 898, referer: https://zbx.site.dev/zabbix/templates.php
[Wed Sep 27 07:29:22.395792 2023] [php7:error] [pid 2573892] [client 194.204.61.131:59097] PHP Fatal error:  Uncaught TypeError: Argument 1 passed to CImportReferencer::setDbItem() must be of the type string, null given, called in /usr/share/zabbix/include/classes/import/CConfigurationImport.php on line 898 and defined in /usr/share/zabbix/include/classes/import/CImportReferencer.php:776\nStack trace:\n#0 /usr/share/zabbix/include/classes/import/CConfigurationImport.php(898): CImportReferencer->setDbItem()\n#1 /usr/share/zabbix/include/classes/import/CConfigurationImport.php(1349): CConfigurationImport->updateItemsWithDependency()\n#2 /usr/share/zabbix/include/classes/import/CConfigurationImport.php(153): CConfigurationImport->processDiscoveryRules()\n#3 /usr/share/zabbix/include/classes/api/services/CConfiguration.php(293): CConfigurationImport->import()\n#4 /usr/share/zabbix/include/classes/api/clients/CLocalApiClient.php(121): CConfiguration->import()\n#5 /usr/share/zabbix/include/classes/api/wrappers/CFrontendApiWrapper.php(97): CLocalApiClient->callMethod()\n#6 /usr/share/zabbix/include/classes/api/wrappers/CApiWrapper in /usr/share/zabbix/include/classes/import/CImportReferencer.php on line 776, referer: https://zbx.site.dev/zabbix/templates.php​

Which points me to https://support.zabbix.com/browse/ZBX-20913 , but since I am running almost latest version 6.0.21 this should be resolved.

Importing new templates works fine, only updating existing template seems to be failing.