multiple item by order to add multiple access groups

-- url of the page with the problem -- : ecnimagerie.fr
-- HikaShop version -- : 4.0.0
-- HikaSerial version -- : 2.2.0
-- Joomla version -- : 3.8.13
-- PHP version -- : 7.2
-- Browser(s) name and version -- : Chrome 69.0.3497.100
-- Error-message(debug-mod must be tuned on) -- : missing groupe

Hello all,

I have a problem, but I do not know if it is the result of a configuration problem or a constraint on the product "HikaSerial".
I use hikaserial to sell access to my website. Indeed, a user can buy 1 or more access to different levels of the site.
it can for example buy the product in Hikashop named "I-Module Orthopedic", the product is connected to a plan that activates the subscription.
the subscription assigns a group to the user for a defined time.

My problem is:
If a user buys 2 products at the same time having 1 different plan: Example: I buy Orthopedic I-Module (which assigns the Orthopedic group for 12 months) + neurological i-module (which assigns Neurological group for 12 months) all pass well rated Hikashop. but the user has only one of the two assigned groups.

I do not understand why. moreover we see in the "Subscription" that the 2 subscriptions are active.

on my website:
1 article Hikashop = 1 plan = access to a group
the user can buy several items at the same time
I would like it to add all the groups at once.

thank

do you want access to the website to test?
I have concrete examples on the site where a user has ordered 2 articles (representing 2 distinct subscriptions) without having the two joomla group of attributed.

Hi,

please see attachments

do you need other information ?