django-autocomplete-light: Cannot read property 'define' of undefined at dalLoadLanguage

Trying to use DAL for formsets in Django 3.1.2.

Problem described occurs in 3.8.1, 3.8.0, 3.7.0dev0 installed via pip. Does not occur in 3.6.0dev1 and earlier (tried through 3.5.1) Does not occur in the sample project (which installs via git)

Set up autocomplete views and form widgets per documentation tutorial. Included {{form.media}} on page as instructed. Upon page load, select widgets are not populated (just single -----------).

Cannot diagnose further as error is thrown in console:

en.js:2 Uncaught TypeError: Cannot read property 'define' of undefined
    at dalLoadLanguage (en.js:2)
    at autocomplete_light.js:106
    at autocomplete_light.js:217

Both Chrome and Firefox highlight that n is undefined at the n.define call at the start of en.js:

var dalLoadLanguage=function(e){var n;e&&e.fn&&e.fn.select2&&e.fn.select2.amd&&(n=e.fn.select2.amd),n.define("select2/i18n/en",[],function()   ... 

Not sure where to begin trying to resolve.