I had the same. There were no obvious errors in the JavaScript console it's just that Chrome seemed to be intercepting the keypresses instead of passing them to the VNC session. For example, pressing the 'r' key caused the page to reload instead of typing the letter into the console.
It turned out that it was caused by a Chrome extension I installed called Vimium that's meant to add additional keyboard shortcuts to the browser.
I was pulling my hair out and redeploying VMs until I thought what if it is the browser?
works in Edge
in Chrome , I can no longer use keyboard or mouse at all, even with extensions switched off.
almost like caret browsing is now on by default. can't find any info on it from Google either - looks like this has been introduced in the latest and not-so-greatest Chrome update. Does anyone know how to override this behaviour ?