Normally doom|show-whitespace-maybe turns on whitespace-mode with a
subset of its features when indent-tabs-mode was different in that
buffer versus it's global default. e.g. If your default was spaces and
you opened a file with tabs.
This is to make it easier to notice whitespace style discrepancies.
However, it have side effects if whitespace-mode/global-whitespace-mode
was already on.