Hello

RE: B-350 dual FMS, Proline-21 install.

We normally sync both units to Number-1 (left side). On todays flight we had GNSS REVERTED error message and it was determined by going to GNSS1 POS page that GNSS1 was in GPS MODE ACQUISITION and only seeing 1 satellite. GNSS2 POS was in GPS MODE NAV and seeing 10 satellites. We then de-synced both FMS units and used FMS-2 as primary (we did not sync the left to the #2/right side in concern for some sort of cross contamination or weird issues) and left FMS-1 as merely a radio tuning device. FMS-2 was used for everything during the flight.

We also have a yellow "TERR" (terrain failure/not working) indicator on the Pilot Displays.

Any ideas on how to resolve this or what did I miss ? We are flying it again tomorrow and will continue to play with it. Back "at base" with avionics and MX support at end of week. Phone calls have gone out but I wanted to ask the forums as a resource for information.

Thank You....