'a potentially dangerous' cookie problem

[MattrCoUk]

I'm trying to use browser-sync on Woindows 10 and experiencing a strange issue with cookie security, both in Chrome and FF.

browser-sync adds some of its code, looks like the local BS settings, to one of my website's cookies

<<BS_START>>{"bs":{"hardReload":true,"scroll":{"x":0,"y":0}}}<<BS_START>>

the web browsers go bananas thinking it is HTML and won't reload the page without clearing cookies

I have tried setting-up chrome://flags/ but no luck there,
I've updated the npm, and bs to latest versions npm 8.1.2 and bs 2.27.7
The project I'm working on is a quite large .net web application, I'm trying to use browser-sync in proxy mode. The localhost is set-up with IIS.

launching BS from command line like so
browser-sync --files ....