v4: elements disappearing (height gets set to 0)

[thisismydesign]

Created a new project with 4.0.0.beta7. Works great locally. On Heroku however, some elements disappear. Their height is set to 0.

This happens only on certain pages but happens 100% of the time there. In one case it's a table body as seen below. As you can see there are elements in the table but they are not visible. The height to tbody is 0.

In another case it's a form:

Screen.Recording.2024-06-19.at.01.32.23.mov

Seems like it's some JS that hides it because it's visible shortly on pageload and then the height is set to 0.

The setup I have is a brand new app with just a few simple things, all standard AA. The code for the form for example:

  form do |f|
    f.inputs do
      f.input :name
      f.input :publisher
    end
    f.actions
  end

[thisismydesign]

Nevermind, this was caused by adblocker due to naming the model ad_slot and having the corresponding class on some HTML elements...