ok i get the issue, vr
i didnt know what you were planing to do with it.

ok instead of using surface shader, assign a regular Lambert shader and try to import in vr. Also maybe dont use .png, use...

if you have access to after effects, try doing it there - a really quick job

if i had to do it in maya,
i would export illustrator file as a hi res .png image (4k) and assign it to a shader in...

I've seen that before with logitech mouses. Usually people just get a new mouse and it solves the issue :)

but to be sure:
first check if middle mouse button works in other applications(check in...