"/gamerule commandBlockOutput true" doesn't make command block output appear in server log

In 1.13.2, I'm trying to get command block output to appear in the server log. I've used commands /gamerule commandBlockOutput true and /gamerule logAdminCommands true, but they didn't help.

For instance, if I want to get periodic logs of a player's position, then I can put the following command in a command block: /data get entity @p Pos

The command block is definitely being triggered, and the output is appearing in the output field of the command block.

This is not a duplicate of MC-121783, because other gamerule commands do work.