If a report is sorted on a custom "Number" field, the sort should use numeric ordering
I observed this while replicating #1081 (closed), so steps to reproduce start out similarly. Of course, it is a different issue, so the steps do become different. The steps are:
(1) Create a custom field on contribution records. Make it "Number=>Text" and flag it as searchable. I called the example "Frobnication Score".
(2) Do a search for some contribution records. Edit a few of them and fill in made-up values for the "Frobnication Score". I happened to use "100", "120", and "90.
(3) Create a "Contribution Detail" report. In "Columns", add the "Frobnication Score". In "Sorting", choose "Frobnication Score" (first) and "Contact Name (in sort format)" (second).
The column is numerical, so you would expect the ordering to be numerical (ascending, "90 => 100 => 120"; or descending, "120 => 100 => 90"). The actual ordering looks like dictionary/alphabetic ("100", "120", "90"). For numeric data, the only useful ordering would be... numerical ordering...
I've observed similar behavior in 5.12.4 and 5.16.alpha1.