Unity Bug: spel start traag / game is loading very slow.

Note: Ik zal mijn bugs reporten in het Nederlands en Engels, zodat BB het ook kan lezen.
Note: I will report the bugs in Dutch as well as in English, so BB can read it too.

How did the error manifest itself?

Game laden duurt bijna 5 minuten.
Starting the game takes about 5 minutes.
Date and time - When did the problem occur?

Bijvoorbeeld: nu (22 juli 2021; 21:00 uur)
Like now (07/22/2021; 9:00 PM CET)
What did you do last?

De browser opstarten
Starting the browser.
Did the problem occur more than once?

Ja, telkens als je de game start.
Yes, every time when you start the game.
Can it be reproduced?

Ja.
Yes.
Have you already done the first steps?

Have you cleared your cache and cookies?

Allemaal gedaan.
All done.
Can you take a screenshot of it?

https://prnt.sc/1efpu4z
Which operating system do you use?

Ik gebruik linux ubuntu 20.04. Maar andere mensen die Windows en Mac gebruiken reporten het ook.
I use Linux Ubuntu 20.04. But other players report this issue too, using Windows or Mac.
Internet provider / Internet speed

Ziggo; Lan 300 mbit/s
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)
Sorry, die werkt niet bij mij.
Sorry, not working.
Which browser AND browser version are you using?

Google Chrome 90.0.4430.212 (Official build) (64-bits)