Event disappeared from Amplitude whilst still in the Amplitude Explorer

One of our Upload Events disappeared a few months ago, and can no longer be found in Amplitude Analytics. This whilst in our code it’s still active in the exact same way, and it also appears in the Amplitude Explorer browser extension when we replicate the event.

We couldn’t find any options in related topics. I hope you can help us out.

How can I help the Event to appear so that I can use it in Analytics?
 

The raw Event JSON

{
 "device_id": "aZFHf--uzObdFkNdCSPVf4",
 "user_id": "1283861",
 "timestamp": 1670577596496,
 "event_id": 786,
 "session_id": 1670577589385,
 "event_type": "Upload Page User Type Clicked",
 "version_name": null,
 "platform": "Web",
 "os_name": "Chrome",
 "os_version": "107",
 "device_model": "Mac",
 "language": "en-GB",
 "api_properties": {},
 "event_properties": {
  "user_type": "stu"
 },
 "user_properties": {},
 "uuid": "905d8c00-b8dc-4288-81cf-691788826794",
 "library": {
  "name": "amplitude-js",
  "version": "8.5.0"
 },
 "sequence_number": 1796,
 "groups": {},
 "group_properties": {},
 "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36"
}

The Event in the Explorer extension