What I check after any broker or platform update
Updates are the most common cause of a setup that worked yesterday and doesn't today. Four things, in order:
1) Reconnect and confirm a test fill, not just a status light.
2) Check that my order types still behave the way I assumed.
3) Confirm the data I depend on is still arriving at the same rate.
4) Run one session small before running it normal.
Item 4 is the one that requires patience and it's the one that has saved me. An update that changes something subtle won't announce itself; it'll just show up in your fills a week later as a mystery.
