Examples:

• I was under the impression that the meeting was going to be held tomorrow, not today.
• He was under the impression that the project had been cancelled, but it was still ongoing.
• She was under the impression that the deadline had been extended, but it hadn't.
• I was under the impression that the store was closed on Sundays, but it's open.
• He was under the impression that the concert had been rescheduled, but it was still on the original date.
• She was under the impression that the presentation was at 2pm, but it was at 3pm.
• I was under the impression that the train was going to arrive on time, but it was delayed.
• He was under the impression that the game was cancelled, but it was still going on.
• She was under the impression that the office closed early on Fridays, but it's open until 5pm.
• I was under the impression that the interview was going to be over the phone, but it was in-person.
• He was under the impression that the package had been shipped, but it hadn't been sent yet.
• She was under the impression that the restaurant closed at 9pm, but it closes at 10pm.
• I was under the impression that the movie was going to be in English, but it was in French.
• He was under the impression that the flight was going to be delayed, but it was on time.
• She was under the impression that the store closed at 6pm, but it closes at 7pm.
• I was under the impression that the book was fiction, but it was non-fiction.
• He was under the impression that the meeting was going to be held in-person, but it was virtual.