This originally showed up when I was looking at https://www.playframework.com/documentation/2.6.x/Migration26 but it doesn't appear to be page-specific -- this is happening on all pages I look at.
I pressed Cmd-f to search for the string "executioncontext" on the page, but after I typed a few characters, the search box went poof -- it simply disappeared.
All subsequent attempts to search had the same effect: the search box appears briefly, then disappears.
It seems to be environmental in some way: I switched to my Chrome window (which I leave open for edge cases like this) to check that it didn't have the same behavior, and was surprised to find my search string already populated there. It's as if Chrome is stealing the search-box focus away from Orion somehow, or as if it's being shared in a buggy way at the OS level.
Cmd-f should work as expected.
Version 0.99.133-beta (WebKit 621.1.2.111.4)
Sequoia (15)