Because of https://github.com/tidyverse/ggplot2/issues/5333 When there're thousands of cells or spots and they're plotted in small panels when multiple features or samples are plotted, having the boundaries can mean that the fill color of the cells or spots becomes invisible as the boundaries take up all the space.
Windows users: Please install Voyager 1.2.7, which has fixed this problem.
Because of https://github.com/tidyverse/ggplot2/issues/5333 When there're thousands of cells or spots and they're plotted in small panels when multiple features or samples are plotted, having the boundaries can mean that the fill color of the cells or spots becomes invisible as the boundaries take up all the space.
Windows users: Please install Voyager 1.2.7, which has fixed this problem.