Pseudo transient analysis?

Your circuit has difficulty in finding a DC solution for .tran to begin with. SPICE, in general, goes through four methods to resolve the DC solution (e.g. if Direct Newton failed, goto Gmin Steeping, then Source Stepping, then Pseudo Transient). Solve with Pseudo Transient indicates that what you are working on poses quite a challenge in obtaining a DC solution.

An example case as your reference.