Data much older than retention policy

Telegraf
1

Hi

I am a bit confused, I have set my default retention policy to 48 hours with shard duration 2 hours.
I updated the RP before starting to write data.
I would expect no data older than Nov 28 (2 days ago).
However I have data much older than that, do i need to do something else to make the retention policy active?

>show retention policies
name       duration       shardGroupDuration replicaN default
----       --------       ------------------ -------- -------
autogen    48h0m0s        2h0m0s             1        true


> select * from gridFrequency order by time limit 10
name: gridFrequency
time                 container device factor id int_value units
----                 --------- ------ ------ -- --------- -----
2020-11-25T13:05:00Z 1         fmeter 10000  1  499950    Hz
2020-11-25T13:05:06Z 1         fmeter 10000  1  499825    Hz
2020-11-25T13:05:11Z 1         fmeter 10000  1  499742    Hz
2020-11-25T13:05:16Z 1         fmeter 10000  1  499652    Hz
2020-11-25T13:05:21Z 1         fmeter 10000  1  499695    Hz
2020-11-25T13:05:27Z 1         fmeter 10000  1  499852    Hz
2020-11-25T13:05:32Z 1         fmeter 10000  1  499933    Hz
2020-11-25T13:05:38Z 1         fmeter 10000  1  500024    Hz
2020-11-25T13:05:43Z 1         fmeter 10000  1  500024    Hz
2020-11-25T13:05:48Z 1         fmeter 10000  1  500116    Hz

Any suggestions much appreciated.