TimeZone Changed! Now Facing Trouble in Feed

We have changed the timezone from United States to Bangladesh for 5 minutes and then watching user post time changed.

However, we have changed the settings again in wordpress and kept "US Time" but currently watching BUG!

"2 new posts available" but this is not an actual notice. No new post found in the feed. Maybe 2 post added during this change or not.

What's the issue and how to solve it?