I found that if you are jumping from a slide to that same slide, on enter actions will work fine every time but only as long as it's set to slide 1.
The moment any other slide comes before it, it no longer works.
I came across this in a massive project that now basically depends on this functionality and then discovered the bug when it came time to add an intro screen.
You can test easily with a blank slide + variable, on enter run an advanced action: increment variable by 1, delay action by 1 second, jump to slide 1. This will count upwards with no problem.
Now just add a slide with a continue button before it and it no longer works.
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