By default, when you change the zoom level, it applies to the tab you have open, so all websites you visit in that tab will have the same zoom level, but if you open the website in a different tab it will have the default or that tab’s zoom level. If you prefer to set the zoom level for websites instead of tabs:

1. Go to Settings > Webpages and make sure Use Tab Zoom has been disabled.
2. Go to the website, where you want to change the zoom level.
3. Use one of the zooming options to change the size of the site.

Then, no matter when you visit the website, it’ll have the zoom level you set for it in the past.