autocomplete stopped working after update

BenTheWicked I had the same problem for weeks, and I don't know exactly which step fixed it, but here's what I tried this morning and now it's working!

1) duplicate the sheet (within the workbook)

2) insert a blank row above the content you're working on/below the headers

3) test autocomplete, and see that it's working on the duplicated sheet

4) delete the duplicate sheet so that I'm back to the original sheet

5) insert the blank row again, below the headers and above the content

6) test and see that autocomplete is working again
7) delete the blank row
😎 now it seems fixed!

The reason I tried this is because my workbook has several sheets, and autocomplete was working as expected on the other sheets but was not working as intended (same as you described) on the first sheet. The issue only came up in the web browser version -- when I switched to the desktop version of excel (to double check settings) it was working without issue, so that didn't seem to provide a path to resolution. I also read elsewhere (while I was trying to diagnose the issue) that autocomplete only works for contiguous (no gaps) cells, so I figured if it's able to autocomplete the headers but not the content, maybe I just need to break the headers away from the content so they're no longer contiguous, that might force autocomplete to sort itself out.

I'm not sure exactly which part of my troubleshooting steps fixed it, but it's fixed for me now in the web browser version on the sheet that was causing troubles. Best of luck to future readers who come across the same issue, I hope this works for you too!