I use: Editor: GNU Emacs 26.3 (build 1, x86_64-apple-darwin18.2.0, NS appkit-1671.20 Version 10.14.3 (Build 18D109))
Hyperbole: 7.1.2
Sys Type: x86_64-apple-darwin18.2.0
OS Type: darwin
Window Sys: ns
In the Hyperbole DEMO file, hitting tab always takes me to the first button, rather than the next one. I traced into the elisp a bit, and sure enough `next-button` does not find the buttons in the file other than the one at the top. Which seems to be due to `next-single-char-property-change` not finding a `button` property change until the end of the file.