In APA format the et al. citation style is used only after all the authors (if there are between 3 and 5) have been cited once. Subsequent citations of the same paper use the et al. format. I can’t see any way to get all authors for the first citation and et al. for subsequent citations.
I’m afraid I can’t reproduce. See my example. It’s a paper with three authors and it appears with all authors the first time cited and with “et al.” the second time.
Can you provide more details for your example? What exact style are you using. How many authors has the paper? What type is the reference, is it a journal paper or something more complex with editors?
I was about to agree with the Allison, because what she said is absolutely true before you format the document. That is, Paperpile does the “et al.” approach no matter what. But, once the document is formatted, everything is fixed. This is probably a reasonable compromise.
I found this thread because I was having the same problem you described Alison. Two things cleared it up, both of which turned out to be user-error. Firstly, as I am writing this paper with co-authors, someone else had placed a first instance citation with all authors listed before mine (mine which then would be the second). But paperpile only recognizes citations that were input using it’s own engine. Since my co-other wasn’t using paperpile, my second citation was considered by peperpile to be the first. The solution ended up being to delete my co-author’s citation and replace it with one generated by peperpile. Then my second citation was properly recognized as the second instance. The second issue was mentioned by someone else- that upon first insertion, the citation is created with full author name array. The fix is to “format citations”. and it get’s fixed.