Ad blocker blocking is becoming increasingly common.
I use the Stylebot extension to strip away this sort of cruft on sites I visit frequently - it's almost always just setting 'display: none;' on a couple of elements.
Another offender is Redfin. I'm running uBlock, and the site loads totally fine with no notifications about adblockers, but the search button is grayed out. Took me a while to figure it out