Hello

I can answer a few of your questions, not all of them.

1- You cannot reply to a message after 24 hours because this is a limitation from Meta (Facebook) itself, not Odoo. Basically, when using the api, you have a 24 hour window from time your customer sends you his last message to reply. Why? no idea, they probably have their reasons (i am assuming spam and stuff).

2- You can only start a new conversation by using a template (also a limitation set by Meta not Odoo).

3- As for the messages disappearing from Discuss, I have the same issue, never could figure out why? I am assuming it is an Odoo thing and not something that we can solve, for now.

Thanks for the answers from Fadi and Kenneth.

I have also found that:

1. The messages in the WhatsApp Module disappear after some time. 
2. 1. Even applying a filter of 1 year doesn't show messages in the past 30 days.
   2. But we know the messages still exist in the database since they are searchable in Discuss. (see Kenneth's post)
3. If the conversation was with an existing Contact, you can go to that Contact's card and look in the Chatter. You will see an OdooBot entry that looks like  :
4. 1. "A new WhatsApp channel is created for this document 12223334444 (Contact Name)
   2. Clicking on the hyperlink opens a Discuss Chat window.

Hi Fadi,

If you go on the discuss module, look at the What's app channel beside it there is a plus icon click on it and search for a number, and you can see the past chats.

Hi Fadi, yes, I did not see the answer till now.. Thank you for y

I'm liking that odoo less and less.. All half solved.. They should stop selling subscription for end customers