Could anyone tell me why the actions on Tempo can't run smoothly after upgra

I found the start form is mobile-enabled but the second is not. When switching, it can't go subsequently.

Simon - are you saying both forms (start and the first user input task) are both mobile enabled? Are they also chained and assigned to the same person?
Also, to confirm, you have Appian 6.7 plus hotfix 1 installed?

Not both, start form mobile enabled, but the second is not. And when starting action on Tempo,the process is completed after the start form(show on Tempo Web UI) shows. Does the second form show in another new window? I think so, but it does not.
Thanks a lot!