Hey, this is a known bug with chat summarization. After summarization triggers, the agent can lose track of the conversation and start treating old messages like new ones.
Your build (v2.6.14, March 8) is from right before the fix shipped. Update to the latest version via Help > Check for Updates, and that should fix it.
For now, if it happens again, the quickest workaround is to start a new chat. You can use @ mentions to pull in the relevant files.
Similar reports: here and here.
Let me know if it still happens after updating.