Hi,
So I was able to see the details for the first bug.
It the same as this one:
github.com/joomla/joomla-cms/issues/32334
It's a shame they dropped backward compatibility for this in Joomla 4.
But the fix is actually easy. You just need to change the line:
<field name="user_group" type="usergroup" size="50" label="USER_GROUP_PRODUCTS" description="GOOGLE_PRODUCTS_USER_GROUP" multiple="true"/>
to:
<field name="user_group" type="usergrouplist" size="50" label="USER_GROUP_PRODUCTS" description="GOOGLE_PRODUCTS_USER_GROUP" multiple="true"/>
in the file plugins/hikashop/google_products/google_products.xml
We'll do that on our end too.
For the second error, I couldn't see it since it requires to first be able to access the settings page of the plugin.