Same problem for me,if we want to keep the truck map updating too the new navcore is not an option so unless some clever person can work out a fix were a bit stuck.
I have an old Go710 and 2 Go730 all with a DSA 9.510 navcore. All three are funtioning as before, no voice problems and no time problems and no satelite problems. Even after making a route the correct time and arrival is updating as usual.
I have 3 gps devices. 3x 940GO Live 9.541 all work ok on all 3. but when i put SD card with truck navcore 9.702 then time reset to 0:00 on all 3 navigation.
btw.
when i have 0:00 this also reset day. So in that moment is 1.january!
I have a Start2 and was using navcore 9.151 to enable use of the usb rdtmc but had the 0.00 time issue, I updated to the 9.541 LE but lost the rdtmc function
my workaround was to use jenitos 9.541 DSA for ONE/XXL.
Haven't tried it with a route yet but it located the satellites ok and the time remained.
No problems with my Go 920 and untouched original Truck-NC NC 9.702. No changes required, the device will work even after 06.04.19 without problems. Time set by hand, everything OK.
Only my ONE3rd (SNr. Y4...GPs GL1) has this stupid time-reset problem. No difference whether 9,510 or 9,541, time is set to 00.00 after satellite detection <grrr>.
Yesterday, I made a trip of 80 Km, back and forth, with my Carminat and my GO 6200, both programmed with the same destination.
At startup, Carminat is equipped with 8.842, for the return, it is equipped with 8.843.
Everything works normally, voice, time, radar positions, etc. rigorously identical to the 6200, which is rather reassuring.