That is rough.
Since I have read your response in the other topic as well, I will try to answer both here so that you don't have to navigate the message board as much. As for the readability of this site, are you able to use the Mac's display settings to invert colors to perhaps see better? If you can't, maybe see if there is a browser extension which increases contrast. I'm sure you wouldn't be able to use it during a test, but maybe it can at least help here.
Also, I imagine you know this, but, in your browser, if you hold down the command key as you press the = (which is also the +) key, the text in your browser should get bigger. Holding command as you press - will zoom out. And holding Command as you press 0 will return the page to the original (100%) Zoom level. You can also adjust your Mac's default font size and your browser's default font size.
In your other response, you mentioned lots of flashing messages. I can't say that I've experienced many of those in Canvas, but I have in Yuja. We do not use Yuja Verity, but we do use one of Yuja's other products. If these alerts are what I think they are, they technically are called Toast Messages (using this term with support centers may produce better results). In our Yuja product, it is possible for individuals to adjust how long those messages stay available. From what I see in the Yuja Verity Support Center, you might not have that ability. Whether or not the instructor does, I don't know. There is also the possibility that the problem is not in Canvas or Yuja, but rather in another system. Sometimes textbook publishers create tests that can be plugged into Canvas. If your instructor uses those tests, it is possible that the problem is associated with the textbook publisher's product instead.
...I imagine that all of this somewhat-technical information is overwhelming...
Perhaps this metaphor will help with understanding how all the pieces work together. Let's say that you are at a restaurant. This restaurant represents your browser (Google Chrome, Mozilla FireFox, or Safari). Canvas is your server/waiter and it is their job to present things to you. The quiz is your meal. Your instructor is the chef. The chef decides how much of each ingredient to add to the meal you have selected. These ingredients are the contents of the quiz and the question types (multiple choice, short answer, etc.). The seasonings (salt and/or pepper, let's say) that the chef adds is your proctoring solution: Everything you experience in that meal from that point on will have a salty and/or peppery flavor. The chef also gets to choose the kind of plate the meal is served on. The plate, is the platform where the quiz was created (i.e. Canvas Quiz or the textbook publisher's tool). If you ordered a large piece of lasagna and it is presented on a thin (so leaky), flimsy, paper plate, you will likely have a different eating experience than if it were prepared on a ceramic plate. Canvas then brings all of the chef's decisions (i.e. the meal on a plate) to you for you to consume. The condiments on the table which you may choose to add to your meal are like VoiceOver or your reading tool. All of these moving parts make it easy for something to not work right, and identifying where the problem lies can be interesting.
With regards to the reading tool disabling during an exam and to your answer selections being made incorrectly because you interacted with the question are items where I can't really suggest where the source of the problem may lie. It could be something that is occurring because of the plate/quizzing platform, the seasoning/proctoring solution, or the condiment/reading tool's compatibility with the restaurant/browser.
The only other thing I can think to recommend to help in your discussions with everyone you have contacted so far as well as the Canvas, Yuja, or other support teams you may contact in the future is to ask your instructor if they help you with the following:
- Create a Yuja proctored quiz in the same system that they use for other quizzes
- Make it worth zero points and assign only you to it.
- Include several question types (multiple choice, fill in the blank, etc.--for best results use the same question types as what is in other quizzes)
- Let you complete the quiz with the understanding that you or someone helping you will record the whole experience with a cell phone or other device.
You can then use that recording in your discussions.
I hope this helps.