Click to Dial no longer functioning - zoomphonecall://{phone}

We use NetSuite's built in telephony system in combination with Zoom's click to dial functionality. 

We have been using zoomphonecall://{phone} without issue for years. As of today, it's no longer functioning. Nothing happens when clicking the phone number link. 

After going over Zoom's developer documentation, I've tried various forms of the URI scheme. Only one I could get to directly dial is "zoomphonecall://+1234567890? ", in which case it of course only dialed 1234567890. Not very helpful.

If anyone has any additional information, I would appreciate it.