Recently we received some reports about "leftover" ACP module entries during update:

Updating from 3.1.10 to 3.2.2, a user reported a non-deleted module ACP_SEND-STATISTICS, which should have been deleted by the migration 

add_help_phpbb.php

The report can be found here (in german): https://www.phpbb.de/community/viewtopic.php?f=145&t=240945

Updating from 3.0.14 to 3.2.2, another user reported a non-deleted module ACP_STYLE_COMPONENTS, which should have been deleted by the migration 

acp_style_components_module.php

The report can be found here (in german): https://www.phpbb.de/community/viewtopic.php?f=145&t=240960