After opened for 1-2 days, the remote trigger would not work anymore. I have to relaunch keyboard maestro and its engine to make it back to work. Is it a bug?
I have the same problem. Except that I can only remote trigger a few times and then it would stop working. I have to relaunch the engine for it to work again. I'm running Version 9.0.5 on MacOS Mojave 10.14.6.
Remote triggers work by Keyboard Maestro Engine having a long-poll connection open to the trigger.keyboardmaestro.com server.
So for it to work, the long-poll connection has to remain active, which requires all the parts of the network between your Mac and the Keyboard Maestro server to behave themselves, to honour the keep-alive packets and appropriate time-outs and what have you.
In theory the keepalive packets should be sent frequently enough to keep the connection alive, but in practice, with various routers and Network Address Translations going on, sometimes they will not keep remembering the connection details and also not bother to tell Keyboard Maestro about the failed connection.
Unfortunately, there is not much I can do about that.