Hi,
Come on, this answer is too easy (but thanks for answering!). This problem appears on Whatsapp, but also on other apps.
As far as I'm concerned, I got the same problem since two days, with many apps: Whatsapp, Fidme, Marmiton, ING bank, CIC bank, Caisse d'Epargne bank, MeteoFrance, Camscanner, Nokians, Tricount... and I didn't try all of the others.
They say "loading ..." (other just show the loading picture) but never start.
Any idea?