Anyone else having trouble uploading files for Unclaimed Moneys?

Tried mobile, tablet, computer. Firefox, Chrome, Microsoft Edge. Updated browsers and java, removed adblockers etc. But I cannot seem to get the "add file" button to pop up. It flashes on the screen for a brief moment and then disappears. I have called and left a message (their number directs you straight to voicemail) and have emailed too. So far no response. I am at my wits end. Help?

PSA: Unclaimed Moneys can be searched for via the WA treasuries website. I hope you have better luck than I have had with the file uploads.