Process gets stuck attempting to create isolates in Dyalog v21.0

[rikedyp]

      )copy isolate
C:\Program Files\Dyalog\Dyalog APL-64 21.0 Unicode\ws\isolate.dws ⍝ saved Tue Jun 23 20:34:26 2026
     isos←ø¨2⊂''

Issuing a strong interrupt opens tracer at [#.[LIB]] #.Conga.LIB.Clt[20]*

[20] r←check ##.Conga.⍙CallR RootName'AClt'a 0

      ]version
 Dyalog  21.0.54076 64-bit Unicode, BuildID 5b3e55ca 
 OS      Windows 11 64-bit                           
 Link    4.2.2                                       
 SALT    2.915                                       
 UCMD    2.8                                         
 .NET                                                
 WS      21.0 

Works in v20.0