Convergence difficulty using Princeton Friction Model

Dear MFIX Community,
I am modeling a pseudo 2D fluidized bed using the TFM . When I invoke the Princeton friction model ( Srivastava and Sundaresan) I experience convergence difficulty with the error DT<DT_min. However I do not experience such problems with Schaeffer friction model. The paper by Passalacqua and Marmo A critical comparison of frictional stress models applied to the simulation of bubbling fluidized beds - ScienceDirect show that the Princeton model is sensitive to the solid volume fraction threshold. I tried playing around with this with little success. I have attached my mfx filesscp.mfx (28.8 KB) and will appreciate any insights.

Have you found any solution to address this issue?