recovery.signal not being removed when recovery complete

I use a script to restore a backup to create a testing copy of the
database. I set the following in postgresql.auto.conf:

recovery_target = 'immediate'
recovery_target_action = 'promote'

In the logs I get "recovery stopping after reaching consistency" then a
moment later "database system is ready to accept read-only connections",
then some entries about restoring log files, then "database system is ready
to accept connections".

I am able to make changes (e.g. CREATE TABLE), yet recovery.signal is still
present. My understanding is that recovery.signal should be removed when
recovery is finished (i.e., more or less when "database system is ready to
accept connections" is logged?), unless recovery_target_action is set to
'shutdown'.

Any ideas? Even just confirming/denying I understand the above correctly
would help.