My demo bots have also been stopping and rejecting orders all day.
My live bots have been working fine.
So it does seem to be a demo only problem (although I don’t have all demo bots running in live, only some).
On the whole I find the live system to be way, way more reliable than demo. Not perfect, but usable in my opinion, with issues being quite rare.
You just have to make sure you monitor everything closely and nip any problems in the bud straight away.
