Since the results I got after training the parental flies looked a bit odd on first sight I decided to take a closer view…

First I excluded some weird animals that either showed a larger preference for one side than avoidance or showed no avoidance two training periods in a row:

Next I compared the behavior of flies that showed avoidance but no learning with the behavior of the remaining flies:

-> Avoidance is almost the same but note the first test period!

Lastly I split the data according to male and female flies. Here is what I got:

-> Looks a bit like there is negative learning in the male flies however I don´t have enough data to be sure…

As an overview here are all the flies (except for the excluded ones) together again: