I may have discovered a part of the cause, though it still leaves me with questions. It turns out 1 particular spreadsheet is the culprit, and the size of the file is likely the primary factor (its about 20MB). I didn't realize I had this spreadsheet open the entire time. If I delete the table in the spreadsheet, the scrollbar and reference formula work perfectly fine. If I close the spreadsheet (or again just delete the table) any other spreadsheet with a scrollbar and reference formula work.

I tried cutting columns of the table and reduced the size from 20 to 13MB (still too large to share here), but the problem persisted. The strangest part to me is that just removing one simple formula fixes the scrollbar, but removing massive amounts of data doesn't -- only removing all of the data. Bizarre!