what is going on with my PS 2 Genesis?

It sounds like you need to do a signal test and see how good your DCS signal is on the track. If its powering up in conventional it isnt seeing the DCS signal.  The toggled siding is a result of the engine missing the DCS watchdog signal when the power is applied to the track (the engine audibly clicks). Toggled power to sidings will cause it to miss that if the power is already on the track and you turn on the siding. If its in conventional and you picked it up and put it back down on the main, its probably just the reverse unit cycling into forward at 18V.

Its possible something is wrong with the board but I would clean track and do a signal test (with the remote and another locomotive) before going further.

An item number would also help, as if its a 5V, there's a higher chance of it being the board vs. a 3V board set.

Item number? How old is the battery?

All my other DCS is working just fine....think it is isolated to this engine

Will take me a bit to find the item number....on the box buried somewhere    battery is old I know.