Absinthe/Socket : JS Error - Uncaught TypeError: Cannot instantiate an arrow function

This problem is keeping me from upgrading to Phoenix 1.6. With require instead of import it works for esbuild with phx 1.5, but no longer with 1.6. I tried contacting the original creator of absinthe_socket through slack, but to no avail. And my JS knowledge is not good enough to rewrite.