I've not encountered any issues getting exit intent forms to work on my pages.
Have you tested on a variety of machines, browsers and screen sizes to rule out issues relating to specific set of end-point conditions? And clearing your browsing data?
Failing that revealing anything, have you tried starting over with a fresh pop-up form?
Hope this helps.
Also, when testing HubSpot pop-up forms that are properly dismissed from the browser being used to test will only reappear AFTER the 'Show dismissed pop-up form again after:' duration setting. It's helpful to use an incognito window when testing, then COMPLETELY CLOSE THE BROWSER AFTER EACH TEST to reset/clear cookies.