Closed captioning doesn't always follow the defined size, and when it resets the size to cover 1/4 of the screen vertically on a 4k monitor at 100% size, if you lower it to 72% which still takes up a huge amount of space making the system not as useful since it can't be offset into the black borders either, you can't set the scale down and have to reset the size by going one up in size, then back down at which point the size is back to 72%.
Closed captioning doesn't always follow the defined size, and when it resets the size to cover 1/4 of the screen vertically on a 4k monitor at 100% size, if you lower it to 72% which still takes up a huge amount of space making the system not as useful since it can't be offset into the black borders either, you can't set the scale down and have to reset the size by going one up in size, then back down at which point the size is back to 72%.