TokuDB table stats row count decreases very fast while adding/updateing data

We run an Percona server with the newest version(5.7.19-17). After a while the cardinality of multiple tables drop to zero. A new created index also have an cardinality of 0 if the existing are zero. I can repair this by do set session tokudb_analyze_mode = TOKUDB_ANALYZE_RECOUNT_ROWS; ANALYZE table myTable; or ALTER TABLE table_name ENGINE=TokuDB; After some tests I found the row count droping over time. As far as I understand the, this influences also the cardinality. The table contains around 800.000 entries and is written nearly the whole day. CREATE TABLE table_name ( val1 char(2) COLLATE utf8_bin NOT NULL, val2 char(15) COLLATE utf8_bin NOT NULL, val3 char(15) COLLATE utf8_bin NOT NULL, val4 mediumint(8) unsigned NOT NULL, PRIMARY KEY (val1,val2), KEY reverse_key (val1,val3) ) ENGINE=TokuDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin ROW_FORMAT=TOKUDB_LZMA; Mostly I write with REPLACE INTO and INSERT ON DUPLICATE KEY UPDATE into this table and update nearly 100% of the data per day. Both insert methods are tested with the same behavior. I start an simple script which just print the calculated row count over time SELECT TABLE_ROWS FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'shema_name' AND TABLE_NAME = 'table_name'; You can see the row count is decreasing very fast. Can anyone explain to me where this behavior comes from and I can handle it?