Improvements needed for multilingual content

The usage of this module in a multilingual site has some problems.
To reproduce the following problems add 2 languages to the website (EN and FR) and make both "Basic Cart Block" and "Basic Cart Count Block" visible.

1)
Create a node in EN, but don't translate to FR
Add the EN node to the cart
Change the site language
Result:
InvalidArgumentException: Invalid translation language (fr) specified. in Drupal\Core\Entity\ContentEntityBase->getTranslation() (line 783 of core/lib/Drupal/Core/Entity/ContentEntityBase.php).

2)
Create a node in EN and translate it to FR
Add the EN node to the cart
Change site language
Result:
- the EN node is displayed on "Basic Cart Block" (correct)
- when you checkout, is the FR node that is displayed in the order (incorrect)
- the placing the order relates to EN node (correct)

3)
Create a node in EN and translate it to FR
Add the FR node to the cart
Result:
- the EN node is displayed on "Basic Cart Block" (incorrect)
- when you checkout, is the FR node that is displayed in the order (correct)
- the placing the order relates to EN node (incorrect)