Hi! I'm James the developer of osci-render - made an account to reply to this
Thanks for the kind words and I'm glad you're making good use of it! I wanted to reply to try and work out why you're having issues with the browser-based software oscilloscope. First thing I'd check is that if you're on Mac OS, try using Google Chrome or Firefox instead of Safari as I've seen people have issues with that in the past. I should add a disclaimer to the website for this!
If that's not the issue it would be great if you could give some more details so I can try and get this fixed
Thanks!