Should, but doesn't. I have the android version with OSM. The tunnel is tagged correctly, but navigation stops in the moment I enter it. Or is there a new version. Last time that happened was about a month ago.
As I actually noticed - on the actual maps (from OSM-source) there are no tunnels shown. Nor the bridges. I can not see which street ist upper an which is lower. Of course I checked the tags in OSM. I think they were shown in former versions correctly. Or I confuse it with OSMand ...
Tunnels and bridges are not shown differently in MapFactor Navigator (as far as I know). On the other hand animation should continue. If you are passing that area more often can you record the NMEA?
I thought I saw tunnels in darker colour in former times, but maybe I'm wrong. I'll check that NEMA, but it would be good, if Navigator realizes tunnels. It is needless and annoying to hear about lost GPS in a tunnel. Last month I was in Italy with lots of tunnels, and every few minutes I heard about lost or found GPS.
Don't know exactly the tunnels, but e.g. on my Italy trip there were several tunnels along highway A14 between Porto San Giorgio (Fermo) and Grottammare, south of it. There I always heard about lost and found GPS.
The next days, I also can check tunnels near my home.
As far as I remember, "lost gps signal" is announced as soon as the signal is lost. It does not mean, that the route is not simulated. Simulation goes on a couple of moments beyond this announcement.
A couple of moments, but not always the whole tunnel, and it is a little too slow. That's bad if you have to change the lane or take an exit in the tunnel. It generally would be better to see, that there is a tunnel, and the "lost GPS" announcement could be suppressed by settings. Of course that's not a big problem but it would be an enhancement of the program.