"This site can’t be reached" error on Chromium

Leaving alone that Chromium in not Chrome - even the "same" web browsers can behave different on Linux vs. Windows - as you already learnt from the VLAN config issue. What is flawless when using Chrome or Firefox on Windows or MaxOS (or even a Android or iOS phone - try it!). I'm convinced there is a tiny flaw on the Smart Managed Plus http/JS code causing the VLAN problem requiring a fix (and not a workaround by using a different browser DanielZhang please).

As the switch doesn't do a redirect from http to https (lack of https ...) the problem is clearly on the browser side. Not enough more and more browser implementations are patronizing users spilling out "insecure" messages near to the URL field up to full page messages with well hidden "bypass" options, the latest "development" goes that far like parsing the URL or prohibiting the submission of forms based on labels and variable names (like login, password, ... or password **** fields), remove less secure ssl, and so on. What is well meant in the Internet facing code, is rubbish on the typically reasonable secure private network. You can do some experimenting, like explicitly call http.//netgear/ without the darned /login.cgi or /login.htm ...  and you might see what happens closely monitoring the http traffic 8-)

Well possible, there is some setting where Chromium can be tuned on being less aggressive or intrusive...