I use Mint on a Surface tablet with detachable keyboard. When I detach the keyboard no virtual one appears automatically, which I prefer. If I need a keyboard there is a quick menubar icon that brings one up. I cant remember if it loaded itself there by default or if I went into settings to make the virtual keyboard icon always in the status bar, but that’s how I manage it.
The keyboard icon always in the system tray may have been an accessibility setting. I honestly don’t remember anymore.