I’ve encountered the both of these on iOS 9 (but not before 9).
However since several forums I use all upgraded Discourse to the latest release at about the same time, I wasn’t 100% sure if it was the OS, browser’s incompatibility with iOS 9, or the new Discourse upgrade, so I thought to wait a bit more to see if any browser update comes out.
(I don’t use Mobile Safari, but the both bugs appear in my browser too).
Sorry - I thought it was clear from my first comment above: I am able to reproduce the two problems reported by GiraffeSilver above, using (among other sites) try.discourse.org.
My screenshots would be identical to his.
EDIT: Posting 2 examples, for completeness (thought to save space…):
EXAMPLE ONE: Browser Copy/Define/Share above Discourse’s Quote Reply:
That’s good to know the full screen thing is by design. I don’t know how others feel about this feature, but it feels a bit “jumpy” - I’d have to go back to use it once again, but I was under the impression that it’s sometimes half the screen size, at other times full screen, without obvious pattern in the way it behaves. @GiraffeSilver why did you think it might be a bug?