I just received the following message from Dynon Support:
Early manufacture GPS 250 built before 2012 have been affected by the GPS Rollover date of April 6, 2019. Symptoms include no date or time being listed in the GPS Fix Status page and clock displayed on SkyView displays is shown as dashes with no valid time. Note: Displays with backup battery installed might still show the date and time, but other problems like winds aloft errors, etc. might exist. Here are the links
to the software to correct this issue.
Really efficient support!