Update issue to Joomla 4

-- HikaShop version -- : 4.5
-- Joomla version -- : 4.03
-- PHP version -- : 8

Hi Support,

We are testing the update to Joomla 4 and we have an issue with Hikashop!
After the update to Joomla 4 we see this error above the page.
We have this error only on these two pages:
- product
- configuration

An error has occurred.
0 Call to undefined method Joomla\CMS\Application\AdministratorApplication::isAdmin()

We have installed Hikashop again but still we have this issue.

Hope you can help us.

Kind regards,
Lumiga

When turning on the "debug system" we saw that the MyParcel pickup plugin was the issue.
So we deactivated that plugin and then the issue was solved!!
But after downloading the newest version and turning the plugin on, the issue was not solved.
Can you reproduce this issue? Hope you can find what causes the issue.

Kind regards,
Lumiga