Could very well be Kerry's being monitored so whoever he's secretly meeting with has to be getting cold feet about continuing to meet with him.
Going by the rumor that a Pelosi codel to Syria led to al Baghdadi, and that Kerry met with the Iranians just before the Soleimani hit, it's likely the Iranians will cut ties with him if anything develops in the near future that could lead back to info discussed at the recent Kerry/Murphy meeting with the Iranians in Munich.
That would mean Kerry is in a pickle between US investigators possibly tracking him and the Iranians, who don't know for sure if Kerry is passing info to US authorities as a double agent. So maybe Kerry is caught out between the threat seizure of his assets in the US for terrorist activity and being snuffed by the Iranians for being the factor in having their assets killed.