keyboard shortcuts – Why has the behavior of my tab key changed on mac

I’m on a mac m1 big sur, yesterday when I was testing with voiceover on a webpage I would

start voiceover
get message I was on webcontent to go into webcontent press VO-Shift-down arrow
do that
then I could press the tab key and tab to the first button in webcontent

I have as far as I know done nothing to change behavior.
Now when I press the tab after getting into web content it selects a button on the browser – it does this in both FF and Safari.

the same thing happens really without voiceover but it is there it is a real problem for me because I need to test keyboard navigation as well.

Even if I focus on something in the page – like opening a dropdown and I hit the tab key it only tabs through the chrome. I need to tab into the page!

Please help it is driving me crazy.