Poor performance in a big chat

Describe your environment

Please specify the following:

• Jami version: at least 6-8 last versions
• Device model: Xiaomi Redmi 8 / Xiaomi poco x4 gt
• Android version: 10/13
• What build you are using: F-droid / Google play

Steps to reproduce

• Can you reproduce the bug: at will
• Actual result: When you have a veeeeryyyy big chat, it is toooo slow. While you are writting message jami can lag and not response at all, you will press on keyboard and jami won't react. It can last for several minutes... Then after lag passes jami shows everything you typed on keyboard. When you send message it doesn't show in the chat monumentally because it will appear 30-120 seconds after you pressed send button. And only after that it will be sent... Android often shows popup Jami isn't responding. Close it or not? It doesn't matter if I press wait because in 85% cases it won't respond anymore... When you try to see previous messages by scrolling up you can end up with crash or just by infinite waiting... Search? It doesn't really work fastly with a new chat but with this big chat just pressing search buttons means death of the app
• Expected result: Blazingly fast like with new empty chat

Additional information

When I deleted jami, android asked me do you want to delete data? It was like 200mb. I pressed yes. When I reinstalled jami and synced to the same account, it started to download that conversation from the second person. It took near 5-10 minutes and showed that the size was ~550mb. New chat works blazingly fast

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