Thanks for quick response.
I wrote "2nd level" but now I see it's backward, so I meant 4th level.

I made screenshots:
2 minutes before Captain. Cannons are 1000/1000


I checked LVL 4, there are no cannons.



I made two slots empty before Cpt. Tobias arrival. I put cannons as an export commodity.
You can see that cannons were sold (-200), but they did not appear in the LVL 4 socket.





And the message is still the same. And no cannons on level 4 items list.





This is my first playthrough, I continue after a campaign with all seasons checked.
I will see if this happens during 'free play'.




This image provides no information, I'm just proud of my town and thank you for the game

I noticed that some items won't level to 2nd level.
Notification shows "export 1000/1000, place it under relevant exporter socket" or something like that but I can't place those items into level 1 socket.

Those some items are: cannons, cans, eyglasses.

Win 10, language version PL, installed all seasons (1,2,3).