Milouze
You don't need to reinstall Iron. But for sure you should install google chrome and check the problem in it. Also you should backup Iron user profile directory because google chrome may be have same user profile directory as in Iron.
Iron user profile directory located here c:\users\yourusername\appdata\local\Chromium just backup whole folder "Chromium" or just rename it then install google chrome and check the problem if it persist in google chrome then it's not Iron fault that you have glitch on it. After checking the problem uninstall google chrome and restore from backup your Iron profile.
Mate I am not sure where to check to be honest.
Just open the link where you have the problem and see what happens.
https://truesteamachievements.com/gamer/Milouze