After regridding, the code sets `dt` on any new finer levels that are created (see [here](https://github.com/AMReX-Codes/amrex-tutorials/blob/2b9b2eed45c8a7c0d58ba6e0454f4982b419e79a/ExampleCodes/Amr/Advection_AmrCore/Source/AmrCoreAdv.cpp#L557-L559)). Shouldn't it also set `istep` and `t_new` as well?
After regridding, the code sets
dton any new finer levels that are created (see here). Shouldn't it also setistepandt_newas well?