What would you do if all communication suddenly stopped with your partner while they’re traveling?

English is not my first language, so please excuse any mistakes. My fiancé is Egyptian, holds German citizenship, and lives in Germany. About a month ago, he proposed to me, and we have been actively planning our engagement and marriage. I live in Egypt. He traveled from Germany to Damascus, Syria, last Monday to attend a friend’s wedding, and then planned to continue on to Egypt. We were in contact for several days, despite unstable internet. Suddenly, all communication stopped. WhatsApp now shows that his number is not registered, yet my messages are still being sent. International calls do not connect at all, and Telegram and Messenger are unreachable. I was told this could be a system or network glitch rather than a block, especially in areas with restricted connectivity. There were no arguments beforehand. Our last call involved a political discussion, which makes me concerned about possible communication monitoring or disruption. He is supposed to arrive in Egypt today at the latest, so this silence is extremely stressful. For those who have experienced sudden communication blackouts while someone was traveling—especially in unstable regions—what would you realistically do next?