When tuning 'import cache', if I 

389-ds-base-2.5.2-1.el9.x86_64
cockpit-389-ds-2.5.1-2.module+el9dsrv+22071+e756ccfb.noarch

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1.Create an instance
2.Select 'Database'->'Import Cache': it displays Autotuning selected, import cache autosize=-1
dn: cn=bdb,cn=config,cn=ldbm database,cn=plugins,cn=config
nsslapd-import-cachesize: 16777216
nsslapd-import-cache-autosize: -1

3.deselect 'autotuning'. It shows 'import cache size: 16Mb' and save
dn: cn=bdb,cn=config,cn=ldbm database,cn=plugins,cn=config
nsslapd-import-cachesize: 16777216
nsslapd-import-cache-autosize: 0

4.select 'autotuning'. It shows 'import cache autosize=0' (not -1) and save. Then it shows 'importcache size: 16Mb' and 'autotuning' deselected
cn=bdb,cn=config,cn=ldbm database,cn=plugins,cn=config" nsslapd-import-cachesize nsslapd-import-cache-autosize
dn: cn=bdb,cn=config,cn=ldbm database,cn=plugins,cn=config
nsslapd-import-cachesize: 16777216
nsslapd-import-cache-autosize: 0  <---- it should be -1 

After being deselected when autotuning is selected again, autosize is set to 0

After being deselected when autotuning is selected again, autosize is set to -1