[2019 07 18 16:00 UT]
Galileo satellites have resumed transmitting signals. According to NAGU 2019027 the system is back online since 2019-07-17 20:52 UTC. All satellites have been declared as usable again. The current service is relying basically on the same satellites as prior to the system outtage. The NAGU subject claims “SERVICE RESTORED (POTENTIAL INSTABILITY)”.
As described in the post before, user devices may exclude Galileo satellites from tracking for a while. This is typically dependent completely on the logic of the receiver device. GNSS receivers decide on the content of the so-called almanac. As with GPS and other GNSS the almanac collection requires tracking one satellite of the system and some time until an older almanac has been replaced. Eventually a restart of the device may help to speed up this replaement process.
(Source: https://www.gsa.europa.eu/newsroom/news/galileo-initial-service-recovery-actions-underway?fbclid=IwAR2_9xI9p_I3He9wIrKx9cMhvL33n_diBfz4yirXFzxyh1VsiHM0fThLsPA and https://www.gsc-europa.eu/notice-advisory-to-galileo-users-nagu-2019027 )