Nested Grid Errors (bug?)

Simple Nested Grid setup in Scriptcase 9.9.
The first grid application pulls from the database with a join (not too complex) and works OK.
The second grid is a simple table (no join).
Configuring the nested grid with the first table pulls only the first record, then displays an error where the nested grid iframe would be (see below). The second grid application runs fine. It asks for the parameter and when given, displays the data correctly.

Is this a bug or did I configure something incorrectly?

Fatal error: Uncaught TypeError: preg_replace(): Argument #3 ($subject) must be of type array|string, device_detail_grid_sub_css given in D:\NetMake\v9-php81\wwwroot\scriptcase\app\ERMM\_lib\lib\php\nm_utf8.php:507 Stack trace: #0 D:\NetMake\v9-php81\wwwroot\scriptcase\app\ERMM\_lib\lib\php\nm_utf8.php(507): preg_replace('#(...', '', Object(device_detail_grid_sub_css)) #1 D:\NetMake\v9-php81\wwwroot\scriptcase\app\ERMM\device_grid\device_grid_grid.class.php(3472): sc_strip_script(Object(device_detail_grid_sub_css)) #2 D:\NetMake\v9-php81\wwwroot\scriptcase\app\ERMM\device_grid\device_grid_grid.class.php(3334): device_grid_grid->NM_grid_device_detail_grid() #3 D:\NetMake\v9-php81\wwwroot\scriptcase\app\ERMM\device_grid\device_grid_grid.class.php(214): device_grid_grid->grid() #4 D:\NetMake\v9-php81\wwwroot\scriptcase\app\ERMM\device_grid\index.php(3264): device_grid_grid->monta_grid(0) #5 D:\NetMake\v9-php81\wwwroot\scriptcase\app\ERMM\device_grid\index.php(5025): device_grid_apl->controle() #6 {main} thrown in D:\NetMake\v9-php81\wwwroot\scriptcase\app\ERMM\_lib\lib\php\nm_utf8.php on line 507