If you Sleep Trained, by any means, does/did it just go out the window when LO gets sick/teething/travels/any kind of change?

We never sleep trained for the night time, but the past week + has been awful! My normal routine: nurse, put her down still awake, walk out. It has entirely stopped working! At first it started with teething. But then she full-blown got sick with her worst fevers, stomach flu, and congestion. She would SCREAM bloody murder as soon as she could tell she was going near the crib. Even when we rock her to sleep (which we haven't done in 1/2 year maybe?), she will wake up as soon as you move and scream. So, for my sanity, we've been co-sleeping for a week. She's pretty much better, but still congested. Was able to put her down like before, last night! But then tonight… oy. Back to the screaming.

All the sleep training stuff says not to start when they are teething or sick or had a change of routine. So does this mean you basically have to start all over again any time there is something that bothers LO?