App is not woking without wifi

For the past month I have no technical problem with this app (I might have even rate this app a good 5/5 star). But this past week, the app suddenly will not work using my mobile data (tried to uninstall/reinstall app, still has a technical glitch). Im using an iPhone 7+ iOS ver. 10.3.1

Angelle_6023 about Moovit: Live Transit App - Bus, Train & Subway, v5.3.0