Error 1054 in Mass Actions filter after Hikashop Upgrade

-- HikaShop version -- : 4.2.3
-- Joomla version -- : 3.9.16
-- PHP version -- : 7.3
-- Browser(s) name and version -- : Any
-- Error-message(debug-mod must be tuned on) -- : 1054 Unknown column 'hk_user.kundennummer' in 'where clause' SELECT COUNT(DISTINCT hk_user.user_id) FROM otm9q_hikashop_user as hk_user LEFT JOIN otm9q_users as joomla_user ON joomla_user.id = hk_user.user_cms_id WHERE (`hk_user.kundennummer` > '500000')
/www/htdocs/w00ad749/previewseiten/arriva/libraries/joomla/database/driver/mysqli.php:665

Hey,

I have a strange filter selection problem in my mass actions. It worked fine in my old version before the last upgrade.
Every time I try to filter a certain custom user field named Kundennummer > 500000 I get a MySQL error.

I do get a certain amount of entries right before I enter the number.

I have a testsystem running and can give you credentials.

Thanks in advance for a tipp.

Best regards
Markus