Just found this out as well.
It’s a significant oversight by OpenAI. This degrades trust in cloud-based services.
Copy/paste isn’t a solution due to truncation and lack of features on other platforms:
• Safari Browser - Shows chats truncated.
• ChatGPT MacOS client - Doesn’t enable selecting text
• iOS - Full history is there, can’t select-all and copy
… Maybe they’re just trying to be first again! First service where upgrading to a better subscription and lose features. 
Seriously … How can we escalate this to the attention of OpenAI?