Piko Navigator losses loco info

Hi Folks,
New to the forum and to DCC.  I just got the piko system with 2 navigators.  When releasing control from 1 handheld to the other, the loco goes back to a picture of analog.  My saved info is not there until I re-enter it and hit M2.
I think this is only happening with 1 of the 2 navigators.  Same software version on both.
Any ideas.
Thanks

Marty,
         reread the instructions.  When saving 'stored' data,  from memory,  you have the choice of saving to either the handset or the central station by pressing either M2 or M3.  I cannot remember which does what.  My Piko failed after only a couple of operating sessions and has gone to God so I cannot check.  By reverting to analogue then there is no digital stored address data on the handset.   When saving data in future, save to M3 and try that.  My handset would save data,  but alas the central station is a piece of the proverbial so do not expect miracles from it.
 
        If saving only to the handset or central station,  I believe that it is only temporary for that operating session (I cannot remember which is the temporary stored data and which is permanent,  M2 or M3?).
 
        In so far as software version,  I believe that it is 1.8 only and this is a Massoth specific software version for Piko only.