Your theme looks incomplete, the browser attempts to download this file (unsuccessfully):
https://insperitytheme.tech/app/themes/sage/public/js/dynamic/node_modules_roots_bud-client_lib_hot_client_js.chunk.js
There is a discussion with a similar error and a potential solution:
https://discourse.roots.io/t/chunkloaderror-loading-chunk-node-modules-roots-bud-client-lib-hot-client-js-failed/24764
Concerning the PHP errors your mentioned: There are no PHP errors when I visit those links, have you already changed/fixed something?