Opatch util cleanup not working

System:

    [oracle@hostname:/opt/oraclegrid/18]$ uname -a    SunOS hostname 5.11 11.4.24.75.2 sun4v sparc sun4v

Database:

    Oracle 18c 18.10 (April 2020 patch), RacOneNode setup

Opatch

    OPatch Version: 12.2.0.1.21

I found out, that a .patch_storage folder in GRID/DB homes takes really much space on file system.

I tried to use opatch util cleanup utility (this utility should clean this folder) but nothing happened. Here is output:

    [oracle@hostname:/opt/oraclegrid/18]$ du -hs .patch_storage/     4.1G   .patch_storage    [oracle@hostname:/opt/oraclegrid/18]$ opatch util cleanup    Oracle Interim Patch Installer version 12.2.0.1.21    Copyright (c) 2020, Oracle Corporation.  All rights reserved.            Oracle Home       : /opt/oraclegrid/18    Central Inventory : /opt/oraInventory       from           : /opt/oraclegrid/18/oraInst.loc    OPatch version    : 12.2.0.1.21    OUI version       : 12.2.0.4.0    Log file location : /opt/oraclegrid/18/cfgtoollogs/opatch/opatch2020-09-13_14-47-13PM_1.log        Invoking utility "cleanup"    OPatch will clean up 'restore.sh,make.txt' files and 'scratch,backup' directories.    You will be still able to rollback patches after this cleanup.    Do you want to proceed? [y|n]    y    User Responded with: Y        Backup area for restore has been cleaned up. For a complete list of