Can't get yarn to stop prefixing every line with "➤"

[ArcanoxDragon]

I have a VS Code workspace with tasks defined for building all of my packages. I'm trying to use yarn workspaces foreach -pi run watch for running TSC in --watch mode for all packages in parallel, but the $tsc problem matcher in VS Code is not matching error messages correctly due to the prefix Yarn is adding to each line - it thinks each file name starts with "➤ ". I have configured enableMessageNames: false in my .yarnrc.yml file, which eliminates the "YN0000" part, but not the actual "➤" character itself.

I found #5152 which suggests that this character is no longer supposed to be written when using yarn workspaces foreach, but it is still printed. I have used yarn set version latest in the root Workspace and all sub-packages, and yarn --version prints 3.5.0, which was released since that PR was merged (the PR itself mentions being included in 3.4.0).

What do I need to do to get Yarn to stop prefixing the output?