I usually save some comments in speed grader. Speed grader seems to have been updated, and this function no longer works properly. I cannot select the comments reliably from the drop-down menu (in Chrome, Edge and Firefox) and in Chrome, even when I save several comments, the drop-down menu only shows the top comment.
Hi Katharine Hunt 
My best advice is to submit a case to Canvas support. (Help>>Report a Problem.) The more cases that are filed, the more quickly the Canvas engineers can see if they can find some reasons for this behavior and/or if it is unique to specific circumstances.
Hope this helps a bit, Katharine, even if it's not an answer to your issue.
Thanks Ken. Glad I am not the only one!
I had the same issue (on Mac, Chrome, Firefox, Safari) and posted this to the Canvas Release Notes comments section (scroll down to comments for October 6th). I also submitted a ticket this morning. It appears from the comments, that you and I are not the only ones.
It's very frustrating!!
Let's hope this can be fixed ASAP!
I'm having the same issue. I noticed the advice given to you about submitting a trouble ticket, but when I attempt to log-in to customer support, I get a log-on error. Doubly frustrating.
I've seen similar messages in the past and they will usually resolve themselves for one reason or another. Also, make sure you are logged into your Canvas site first and then see if that makes a difference.
Thanks Ken. So far, it has not cleared up yet, but I'll keep trying.
Thanks for your patience, everyone! As noted in a related discussion (Speedgrader Comments Malfunctioning? ), a fix for this has been deployed to beta, so it should be working in production soon.
Thanks for your patience, everyone! We've deployed the fix associated with the issue of saved comments in freeform rubrics (described in the Canvas Release Notes (2018-10-27)) and you should now see it in production.
Explanation: When a comment was saved for reuse in free-form comments, the saved comment would not display in the comment menu until the page was refreshed. Canvas code has been updated to retain all saved comments for reuse in SpeedGrader.
Thanks for your patience, everyone! We've deployed the fix associated with the issue of saved comments in freeform rubrics (described in the Canvas Release Notes (2018-10-27)) and you should now see it in production.