CLPR behaves differently in SWISH than in SWIPL


With this program:

:- use_module(library(clpr)).    
eq(X = 1 + 1).

When I run ?-eq(EQ), doMyEq(EQ). on my laptop with SWIPL (version 8.2.1) i get
EQ = (2.0=1+1) ;

But with the same program and query, in SWISH i get the error:

Arguments are not sufficiently instantiated
[2] 0> -_1550/1.0
[1] nf_r:submit_eq_c1([],v(1.0,[...]),_1604) at /home/swish/lib/swipl/library/clp/clpr/

Does anybody know what’s happening? I would like to know because I am trying to build a meta interpreter for use in SWISH that doesn’t need call/1.

Kind regards, JCR