I found a similar problem with RUT955, the same firmware 06.02 (the latest), but the issue is with NMEA forwarding.
I'm forwarding NMEA sentences over UDP to a localhost port, at which my application is listening.
It works for some time when gpsd is restarted, but after around ~1 h the forwarding stops for some or all sentences.
Does this fix which you posted affect NMEA forwarding, too?
Another issue: When enabling NTP GPS synchronization, gpsd seems to fail totally. Running gpsd -d shows an error, unable to read uci enabled flag or something like that. Maybe the config is not written correctly when GPS time sync is enabled?
Also, even when it's working I'm regularly seeing some error lines when running gpsd -d: Reading failed, lost xx bytes