Meetings fail to book when the calendar integration is disconnected, availability rules leave no open slot, a double-booking race occurred, or the invite bounced. Check the calendar connection and the booking's status in the conversation.
Check the calendar connection
Settings → Integrations → Calendar. If it's disconnected or the token expired, booking can't write to the calendar. Reconnect and re-test. This is the most common cause of a meeting that "agreed" in the thread but never appeared.
Availability and conflicts
If your availability rules (working hours, buffers, daily limits) leave no valid slot, or the slot got taken between offer and confirmation, the book fails. Widen availability or loosen buffers if legitimate slots are being blocked.
Invite delivery
Occasionally the calendar invite itself bounces or lands in spam on the prospect's side. Confirm the recipient address and that the invite was sent; resend from the conversation if needed.
Fixes and verification
Reconnect the calendar, adjust availability, and re-offer times. After fixing, book a test meeting end to end to confirm it writes to the calendar and both parties get the invite. Reply-to-meeting automation (see Reply-to-meeting automation) depends on this working.