Entering/Updating products with quantities other than -1 result in error message

-- HikaShop version -- : 4.3.0
-- Joomla version -- : 3.9.19
-- PHP version -- : 7.3.14-1
-- Browser(s) name and version -- : FireFox 77.0.1
-- Error-message(debug-mod must be tuned on) -- : 0 Call to undefined method hikashopProductClass::saveRaw()

This happens in front office (vendor control panel - add/update product) and in back office (administration - Hikashop Products add/update)

Although it appears that the product update is saved correctly.

I eliminated numerous possible causes, the problem only occurs when quantities are used. (and not using quantities is not an option)

Thanks in advance for looking into this.
This freaks out my vendors, obviously (!)
Please give it priority.

in front office (updating a product that hat quantity 1 or higher) - in front office, the product is *NOT* updated

0 Call to undefined method hikashopProductClass::saveRaw()
Call stack
# Function Location
1 () JROOT/plugins/hikashop/variants_quanity_synch/variants_quanity_synch.php:63
2 plgHikashopVariants_quanity_synch->_updateProduct() JROOT/plugins/hikashop/variants_quanity_synch/variants_quanity_synch.php:30
3 plgHikashopVariants_quanity_synch->_processProduct() JROOT/plugins/hikashop/variants_quanity_synch/variants_quanity_synch.php:12
4 plgHikashopVariants_quanity_synch->onAfterProductUpdate() JROOT/libraries/joomla/event/event.php:70
5 JEvent->update() JROOT/libraries/joomla/event/dispatcher.php:160
6 JEventDispatcher->trigger() JROOT/libraries/src/Application/BaseApplication.php:108
7 Joomla\CMS\Application\BaseApplication->triggerEvent() JROOT/administrator/components/com_hikashop/classes/product.php:2742
8 hikashopProductClass->save() JROOT/administrator/components/com_hikamarket/classes/product.php:1288
9 hikamarketProductClass->save() JROOT/administrator/components/com_hikamarket/classes/product.php:571
10 hikamarketProductClass->frontSaveForm() JROOT/components/com_hikamarket/controllers/product.php:553
11 productMarketController->store() JROOT/components/com_hikamarket/controllers/product.php:91
12 productMarketController->save() JROOT/libraries/src/MVC/Controller/BaseController.php:710
13 Joomla\CMS\MVC\Controller\BaseController->execute() JROOT/administrator/components/com_hikamarket/helpers/helper.php:1695
14 hikamarketController->execute() JROOT/components/com_hikamarket/hikamarket.php:76
15 require_once() JROOT/libraries/src/Component/ComponentHelper.php:402
16 Joomla\CMS\Component\ComponentHelper::executeComponent() JROOT/libraries/src/Component/ComponentHelper.php:377
17 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/SiteApplication.php:194
18 Joomla\CMS\Application\SiteApplication->dispatch() JROOT/libraries/src/Application/SiteApplication.php:233
19 Joomla\CMS\Application\SiteApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:196
20 Joomla\CMS\Application\CMSApplication->execute() JROOT/index.php:49

updating in backoffice -->
An error has occurred.

0 Call to undefined method hikashopProductClass::saveRaw()
/var/www/vibel.be/public_html/plugins/hikashop/variants_quanity_synch/variants_quanity_synch.php:63

Call stack
# Function Location
1 () JROOT/plugins/hikashop/variants_quanity_synch/variants_quanity_synch.php:63
2 plgHikashopVariants_quanity_synch->_updateProduct() JROOT/plugins/hikashop/variants_quanity_synch/variants_quanity_synch.php:30
3 plgHikashopVariants_quanity_synch->_processProduct() JROOT/plugins/hikashop/variants_quanity_synch/variants_quanity_synch.php:12
4 plgHikashopVariants_quanity_synch->onAfterProductUpdate() JROOT/libraries/joomla/event/event.php:70
5 JEvent->update() JROOT/libraries/joomla/event/dispatcher.php:160
6 JEventDispatcher->trigger() JROOT/libraries/src/Application/BaseApplication.php:108
7 Joomla\CMS\Application\BaseApplication->triggerEvent() JROOT/administrator/components/com_hikashop/classes/product.php:2691
8 hikashopProductClass->fullSave() JROOT/administrator/components/com_hikashop/classes/product.php:665
9 hikashopProductClass->backSaveForm() JROOT/administrator/components/com_hikashop/classes/product.php:50
10 hikashopProductClass->saveForm() JROOT/administrator/components/com_hikashop/helpers/helper.php:2014
11 hikashopController->store() JROOT/administrator/components/com_hikashop/controllers/product.php:112
12 ProductController->save() JROOT/libraries/src/MVC/Controller/BaseController.php:710
13 Joomla\CMS\MVC\Controller\BaseController->execute() JROOT/administrator/components/com_hikashop/helpers/helper.php:2178
14 hikashopController->execute() JROOT/administrator/components/com_hikashop/hikashop.php:72
15 require_once() JROOT/libraries/src/Component/ComponentHelper.php:402
16 Joomla\CMS\Component\ComponentHelper::executeComponent() JROOT/libraries/src/Component/ComponentHelper.php:377
17 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/AdministratorApplication.php:101
18 Joomla\CMS\Application\AdministratorApplication->dispatch() JROOT/libraries/src/Application/AdministratorApplication.php:159
19 Joomla\CMS\Application\AdministratorApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:196
20 Joomla\CMS\Application\CMSApplication->execute() JROOT/administrator/index.php:51

[SOLVED] Thank you. That worked fine.