Assert error 1000 in Redshift

Hi, I made a simple SP that performs as deep copy of a table, like described here https://docs.aws.amazon.com/redshift/latest/dg/performing-a-deep-copy.html. The SP is simple, it takes schema name and table name as input parameters, then create a new table via CREATE TABLE (LIKE), then inserts data from old table into the new, then drops the old table, and finally renames new table as old. When i ran the SP on a table for the first time, it worked fine. However, any consequent run of the procedure on the same table gives Assert 1000 error and it is related to insert data part: ERROR: Assert Detail: ----------------------------------------------- error: Assert code: 1000 context: table - query: 282270297 location: funcs_int.cpp:88 process: query0_99_282270297 [pid=16374] ----------------------------------------------- Where: SQL statement " INSERT INTO ...blabla... [ErrorId: 1-64903d7e-333bc0482dcd82f552aab048].

What is going on and what should i do? The deep copy table is accessible for querying, but any attempt to insert new data is giving assert error, so it is broken or something. How do i fix it and do proper deep copy that works?

PS. maybe it is important that the subject table has identity column, so when i insert data from old table into the new one, i ignore the identity column, i.e. i do not use INSERT INTO SELECT *, but use INSERT INTO (col1, col2, ...) SELECT col1, col2,...