attach partition to parent table with default partition accessexclusive

Hi ,
We have a table wbxdata (xxxx...) partition by range(starttime) , and have a default partition, now we want to add a new partition and move the data from default partition to new added partition.

Begin;
Alter table only wbxdata ... detach partition wbxdata_pdefault; ---from here, accessexclusive lock on wbxdata_pdefault default partition, and it block all query on parent table wbxdata.
Insert into wbxdata_p2305 select * from wbxdata_pdefault where starttime >= '2023-05-01 00:00:00'::date and starttime < '2023-06-01 00:00:00';
Delete from wbxdata_pdefault where starttime >= '2023-05-01 00:00:00'::date and starttime < '2023-06-01 00:00:00';
Alter table only wbxdata attach partition wbxdata_p2305 for values from ''2023-05-01 00:00:00' TO '2023-06-01 00:00:00';
Alter table attach default partition;
End;
Is it expected to see all query even select on parent table wbxdata got blocked , when detach default partition and attach default partition ? Postgresql 14.7 version.

Thanks,

James