Your binding reaction "Ligand binding" has a flux of:
1.5882832785960066 * 10^-12
at time 0, which means that you would need approximately 10^12 minutes
to see a change of 1 in the numbers of MOR or MOR:L.
Please check the rate constants in your reactions.
Stefan Hoops, Ph.D.
Research Associate Professor
Biocomplexity Institute & Initiative
University of Virginia
995 Research Park Boulevard
Charlottesville, VA 22911
Phone: +1 540 570 1301