Analytics dataset shows NaN

In my dataset I currently have collected data:

MariaDB [database]> select count(*) from prefix_analytics_facts where user_id = 'user' and dataset = 10 ;
+----------+
| count(*) |
+----------+
|     2500 |
+----------+
1 row in set (0.001 sec)

Yet in Nextcloud this count is shown as NaN (Not a Number):
Untitled
I assume this is a bug?