Restore legacy alerts , converting to unified alerts - all alerts skipped

I had Grafana 8.3.4 and settings in config file for alerts:
[unified_alerting]
enabled =
[alerting]
enabled =

I don’t change anything and after restart Grafana start conveting all my alerts to unified alerts and skipped 377 my rules

lvl=info msg=“The state of unified alerting is still not defined. The decision will be made during as we run the database migrations” logger=settings
0 lvl=warn msg="falling back to legacy setting of ‘min_interval_seconds’; please use the configuration option in the unified_alerting section if Grafana 8 ale
0 lvl=info msg=“Config loaded from” logger=settings file=/usr/share/grafana/conf/defaults.ini
0 lvl=info msg=“Config loaded from” logger=settings file=/etc/grafana/grafana.ini
0 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.data=/var/lib/grafana”
0 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.logs=/var/log/grafana”
0 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.plugins=/var/lib/grafana/plugins”
0 lvl=info msg=“Config overridden from command line” logger=settings arg=“default.paths.provisioning=/etc/grafana/provisioning”
0 lvl=info msg=“Path Home” logger=settings path=/usr/share/grafana
0 lvl=info msg=“Path Data” logger=settings path=/var/lib/grafana
0 lvl=info msg=“Path Logs” logger=settings path=/var/log/grafana
0 lvl=info msg=“Path Plugins” logger=settings path=/var/lib/grafana/plugins
0 lvl=info msg=“Path Provisioning” logger=settings path=/etc/grafana/provisioning
0 lvl=info msg=“App mode production” logger=settings
0 lvl=info msg=“Connecting to DB” logger=sqlstore dbtype=sqlite3
0 lvl=info msg=“Starting DB migrations” logger=migrator
0 lvl=info msg=“Executing migration” logger=migrator id=“clear migration entry “move dashboard alerts to unified alerting””
0 lvl=info msg=“Executing migration” logger=migrator id=“remove unified alerting data”
0 lvl=info msg=“Executing migration” logger=migrator id=“undo update dashboard_uid and panel_id from existing annotations”
0 lvl=info msg=“migrations completed” logger=migrator performed=3 skipped=377 duration=208.465323ms

And now I see only 3 alerts in inified alerts , I want to restore legacy alerts - and set

[unified_alerting]
enabled = false
[alerting]
enabled = true

But after restart I see new menu for alerts and don’t see all my legacy alerts and old alerts menu . I use sqlite3 as db and I try to change file of grafana.db from backup - But still each time when I restart grafana I see that database doing migrations and skipping all my legacy alerts
vl=info msg=“migrations completed” performed=85 skipped=377 duration=1.184435504s

How could I restore my old legacy alerts ? Thanks