Hi Andrew, sorry to hear about this issue. I tested a handful of 4x and 3x tile layer samples using Edge, and I did not see any errors. Here are my Edge and OS versions:
Windows 10
Microsoft Edge 42.17134.1.0
Microsoft EdgeHTML 17.17134
Could you try updating your version of Edge, or post a link to a hosted sample so I could test the same one you are seeing the error with?
-Noah