I'd say it has worked the past 4-5 times for this specific error code/circumstance (including my only win in the Expert division via the Overstuffed Showdown on the final hole in the 2nd to last match) . I think I came across a Forum topic back in the middle of last year to where it was noted that the 'Cancel' option was a viable one once again, so I took a chance and it's been working ever since.
https://youtu.be/9p1H7ln50OQ
I too was extremely irritated repeatedly hitting the 'Retry' option, having nothing happen, subsequently getting credited for three bogeys for the match and then having to request WGT to refund my entry fee rather than me having the opportunity to earn it back. Thankfully now that's no longer needed.
And like I stated originally, there are still other frustrations within this event, but this specific one seems to have an easy fix of just some extended patience (and making sure you still have that timeout to use). :)