Unity bug - graphics showing upgrading buildings

English tech description down below:
Nederlands: Er zijn meerdere gebouwen die aangeven in upgrade te staan, terwijl dat niet zo is.

How did the error manifest itself?
The graphics of the game are showing multiple buildings with an upgrade possibility sign whilst these are not being upgraded and also not upgradable.

Date and time - When did the problem occur?
When clicking the weekly boat and opening the menu.
10.12 24-7-2021 on Woestewoud

What did you do last?
No previous action. Reproduced the error twice with new login into the game.

Did the problem occur more than once?
Yes

Have you already done the first steps? + Have you cleared your cache and cookies?
Yes cleared history and cookies.

Can you take a screenshot of it?
https://snipboard.io/khIRtO.jpg
https://snipboard.io/6QSFse.jpg

Which operating system do you use?
Windows 10

Internet provider / Internet speed
Broadband ~100Mbs - speedtest

Internet access
LAN

Please attach Screenshots of the Dev Console. Please send Screenshots of the "Inspector" tab AND the "Console" tab.
(Press F12 in the browser while you experience the error)
I guess that is not really helpfull for this one.

Which browser AND browser version are you using?
Chrome - Versie 91.0.4472.164 (Officiële build) (64-bits)

Also, kindly add reproduction steps, and feel free to add any details you find relevant.
No actions required. It is just like this without any actions.
It applies to multiple buildings and submitted 2 examples.

Confirm this with Linux Ubuntu 20.04, same problem. I tried to move the storage unit building (don't know the english ingame word for it) to the star menu and build it again. Now it is stuck on level 1. Won't upgrade anymore, although the building should upgrade when you finished Easter quests (which I finished). Still the building has the upgrade-icon-problem described above.