I have had a look at your project. My first question is, why a transient simulation? This looks like a simulation where you are only interested in the end result and not a transient response in which case a steady state simulation can be used (it is less resource intensive and more stable). If you feel you need a transient case, then your time step length (under simulation controls) must be much much shorter than what it is now.
Lastly, the boundary condition of elastic support, why do you choose this on the face of the Viton seal? It will already deform easily due to its low young’s modulus. The fixed or elastic support gives the simulation a reference point to calculate the thermally induced displacement.I think (i’m not certain) it may be incorrect to define an elastic boundary in an interface between two bodies as to me it seems like a physically impossible scenario. Try making this boundary fixed, or if that does not work then try deleting this boundary condition and replacing it with a fixed support on an external surface.
Let me know how it goes!