Many of these issues do exist, and are probably somewhat related.
Quote from: Maverick on 21 02 2021, 17:09:23 - Plugin disconnects after a while in silence
Quote from: ghazan on 22 02 2021, 13:29:54 - Yes, as expected. You need StatusManager plugin, which keeps a protocol connected.
(Turns out i cant figure out how to properly quote a message for some reason.)
StatusManager helps when the protocol knowingly disconnects. But there are many cases where Miranda thinks it is online, and actually isnt. In some of those cases, StatusManager cant do anything because Miranda still believes that it has not lost connection. (A state which can persist for many hours unnoticed.)
I can confirm:
Miranda's Steam protocol will occasionally experience a silent disconnect. When this happens Miranda still shows you as being online, and your friends still show as online / playing their games, but the client never receives another update. If you try to send a message while in this state, it will fail and tell you that you are offline, but will not actually set the protocol status to offline or attempt to reconnect you. (I have mixed feelings about whether or not it should.)
Without knowing the cause to this problem, one hacky workaround might be to assume that if Miranda has not received any update data from Steam within a certain time range (5-10 minutes?) that something has gone wrong and that it should try to reconnect.
One of the problems that Miranda has with Steam though is that sometimes when connecting, it downloads (some) data, some messages, some friend information, and then disconnects immediately after, though again it does not realize it has been disconnected, so you only know that you are not actually online when you see someone you know should be online, or when you try to send a message (because it looks like you are online.)
Another issue that exists:
Miranda does not show custom game statuses, so anyone who is playing a "Non Steam Game" through Steam will show as if they are not playing any game at all.
You also mentioned this issue: "NEW: Messages are not received properly anymore (i have Steamchat on my Smartphone and i get all Messages, but with MIranda, more and more often i dont receive any)"
There was a bug that was fixed back in January which i reported:
#2692 - "Messages received by Steam client first are not downloaded after logging into Miranda" And that was fixed on Jan 20, 2021. If you've not updated your development build since then, chances are you do not have that fix. (I dont know when the stable was last updated admittedly.)