Hi @Aris Gkintonis,
Thank you for posting in this community.
My coworker and I tested copying items with shortcuts in grid view, but we were all able to do it properly.
We need to work together to narrow down and resolve the situation. So, please kindly provide more information below to let us work further.
1.Whether all SharePoint lists have the same problem? You could create a new SharePoint list to check.
2.Check if the same issue occurs with other SharePoint site collections.
3.Convert the list to classic mode and then see if the problem persists.
I actually learned that shortcuts work on classic experience (But it actually works in the modern experience in testing as well). You can change the experience to classic. If you still want to use modern experience, then you can try exporting the data to excel and copying the contents of excel. This also solves the problem of shortcuts not being able to copy multiple items at the same time.
Export to Excel from SharePoint or Lists
It is much easier to manipulate items in an excel file.
Also adding new item is visible in my grid view.
First, you need to make sure that you have Contribute permission level or higher for the list and that your permission to add items is not disabled. Please check your permission level on the list by going to List Settings > Permissions for this list > Check Permissions and entering your name or email address.
Second, you can check in other lists or site collections to see if the problem still exists. If it still exists, please send me a screenshot of the list, it might better help me analyze the problem.
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