OnePlus
Enable or Disable Spell Check auf OnePlus
Spell check on OnePlus phones runs inside Gboard, separate from auto-correction. It underlines words it does not recognize instead of replacing them, so you notice typos without losing control over the text you typed.
Because both functions are independent, disabling auto-correction does not remove the underlines, and switching off spell check does not affect auto-correction. If you want a clean keyboard without red squiggles while typing notes or code, turning spell check off is the faster fix. If you rely on the underlines to catch mistakes before sending a message, keep it enabled.
Where to find the setting
Open Open the Settings ➔ Tap on System ➔ Tap on Languages & input ➔ Tap on Virtual keyboard ➔ Tap on Gboard ➔ Tap on Text correction ➔ Enable or disable Spell check. The toggle applies system-wide, across every app that uses the keyboard.
If the option is greyed out, check that Gboard is selected as your active virtual keyboard, since the setting only appears for the keyboard currently in use.