Thanks @lizzieinvancouver , I think that is the issue!
The model estimates look much better:
Variable Parameter Estimate 2.5 97.5
1 mu_grand 15.0 13.1826762 10.8605118 15.6679884
2 sigma_sp 5.0 4.9062756 3.5509274 6.8316180
3 sigma_study 2.0 1.9663274 1.4023942 2.8284024
4 sigmaResp_y 5.0 4.9497511 4.6061570 5.3291774
5 muCueSp -15.0 -15.4105784 -22.4536695 -8.3219147
6 muResSp 80.0 73.4124964 64.5280508 81.9648668
7 sigmaCuesp 4.0 5.4873654 3.8633931 7.8094396
8 sigmaRespSp 20.0 21.2382161 17.2866958 25.9841407
9 betaTraitCue 0.3 0.3237353 -0.2031581 0.8470558
