This problem sounds like the same problem posted as "Text disappearing and reappearing while typing MS word": https://answers.microsoft.com/en-us/msoffice/forum/all/text-disappearing-and-reappearing-while-typing-ms/e8419e98-6e79-42bd-bd95-5363699ab545?page=1&messageId=2f09cc0b-6fc8-484f-96e0-18f08cf125a3
A solution posted there by ScottCrandom sounds very promising; I'm about to try it. In summary:
"Close the affected program. Add the affected .exe. file to the "Manage 3D settings" and "Program settings" tab of Nvidia control panel. Then for the affected program, enable "Ultra" low latency mode.
For AMD GPUs enable low latency mode for the affected program in the AMD graphics settings application."