Strange. I can see both the blueprint and your orange throwing axes in your inventory on our side.
Could you try renaming the Vermintide 2 folder in your App Data to something temporary (like “Vermintide 2 OLD”), then reboot the game?
C:\Users\YOURNAME\AppData\Roaming\Fatshark\Vermintide 2
You will lose your settings (which is why we backed up your folder by renaming it!) but it’s worth testing this to see if the items appear in your inventory again.
If it helps (or not), just delete the newly created Vermintide 2 folder and rename the old one back to normal in order to restore your settings.
Let us know how this goes.