Same here, see the issue on iOS on both an iPad Air 4th Generation and an iPhone 16 Pro. Playback speed changes in the browser work fine (same devices, Firefox mobile). Also tested on desktop and no issues. I tried turning “Allow Direct Play” off in the Video and Audio settings and nothing changed.
Plex Server Version 1.42.2.10156 (Docker)
iOS Client Version: 2026.1.0 (1537)
iOS Version: 26.2.1