The grain deal in practice is that the Turkish Navy mine sweeps Ukrainian harbors and escorts the grain shipments. Russia stays out of the way and avoids engaging the Turkish armed forces.
What part of the deal Putin thinks he can withdraw is ambiguous.
CAUTION! regarding The New Atlas referenced in Comment #22:
Do not be mislead. This comment is from The New Atlas (previously Land Destroyer) based in Thailand.
The New Atlas source is noted for inaccuracy & unreliability. This source may reference a legitimate news source. However, ultimately will spin any factoid into a commentary of systematic misinformation.
The non-use of a balanced geopolitics perspective defines this commentary as active disinformation. Similar articles may be found on: Russia Insider, Land Destroyer Report, and Activist Post. Totally your prerogative to select your personal sources for news information.
Be aware this source provides only disinformation.