Additional Controls dropdown not showing as expected

[iPurpl3x]

Since I updated some Flarum instances to Flarum 1.7, I started noticing the following issue:

When opening the "Additional Controls" dropdown by clicking the "+" button in the rich text editor, the dropdown alters between opening on the top or on the bottom, when on the bottom it is not visible.

On the screenshot, one can see that on the bottom there is an open dropdown that is almost invisible.

Instance: https://community.glowingblue.com/
Flarum version: 1.7.2
Rich Text version: 2.1.7

(cc @askvortsov1)

[Petersoj]

Can confirm this is happening on my forum instance as well. Fresh install.

[Petersoj]

Custom forum CSS as a temporary fix:

.ProseMirrorMenu ul.Dropdown-menu {
  top: auto;
  bottom: 100%;
}

.ProseMirrorMenu ul.NodeTypeDropdownMenu > div[role="tooltip"] {
  display: none !important;
}