Webchat doesn`t show the server "say XYZ" message in the webchat.
Every User shows in the chat

I don't think this deserves to be a bug. /say is a command, not a message.

These aren't chat messages, I wouldn't expect dynmap to relay them.

You could update your aliases file so "say" invokes

• minecraft:say
• dynmap sendtoweb

Then they'll appear in game as well as on dynmap

It does appear ingame if send ingame from a player.
But not if ussiued from Terminal.

Thanks

Sending messages from terminal with 'say' is not the same as a player chat event, which is what dynmap listens for. If you want the functionality where dynmap broadcasts the 'say' messages too, try implementing what I said above.