CRA and banking institution used, everything accepted and ENoA printed. Redirected and given the error 'There was an issue downloading Express Notice of Assessment'

Sounds like a momentary issue with TurboTax's connection to the CRA's ENOA service.

You can always confirm the status of your return and see your ENOA or NOA in your CRA My Account: https://turbotax.community.intuit.ca/replies/2647719