When you have split views, the maximize icon has the correct tooltip; however, once maximized, the maximize icon still has 'Maximize terminal' It should be either 'Un-maximize terminal' or perhaps "Restore terminal sizes' SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: (available in About System) KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION
Can confirm this is still an issue as of 20.08.1 Line of code that matches (from my brief search) https://invent.kde.org/utilities/konsole/-/blob/master/src/widgets/TerminalHeaderBar.cpp#L95
A possibly relevant merge request was started @ https://invent.kde.org/utilities/konsole/-/merge_requests/262
Git commit 7e99f5cf93b308518398ad2555c936899e488ef0 by Carlos Alves. Committed on 31/10/2020 at 19:40. Pushed by hindenburg into branch 'master'. Fix Maximize/Restore split terminal tool tip FIXED-IN: 20.12 M +5 -0 src/widgets/TerminalHeaderBar.cpp https://invent.kde.org/utilities/konsole/commit/7e99f5cf93b308518398ad2555c936899e488ef0