It’s been happening for a long while now.
When I choose a time slice and “enter” a PVE, the loading screen pops up and I don’t get entered into the PVE but brought back out to the menu screen.
The only way to resolve this is to force close the app and reopen it. But I highly doubt the mechanics are supposed to work this way, amiright?
Btw I’m on iPad version 8.1 if that helps.
This has been happening for a while now. I still see it on iOS 9.1.
Happens erratically on Android as well. I haven’t been able to discern a pattern around when it occurs, but the workaround is so simple (close and reopen) that I don’t pay it much mind.
Just noticed that my thread slipped out of the first page, perhaps others can comment to confirm this is happening so the Devs can take a look?
Not that it cannot be rectified by the end-user by force-closing, but we shouldn’t have to. : 
I have it happen, but it seems to be when I have a weaker signal. It’s like it sends the chosen time, but doesnt receive the confirmation, until playing a match or restarting.
Device: iPod Touch 5th Generation
OS: iOS 8.4.1
Details: I started having this happen during these last 2 PvEs (Unstable ISO and Dark Avengers Heroic) where picking a time slot automatically booted me out of the PvE screen as if I never chose anything at all. Happened repeatedly until I force-closed my app and then re-opened it. This did not happen in Enemy of the State, however.
Happens on steam as well.
happens on Steam version.
Every. SINGLE. TIME.
close & re-open doesn’t help. I just have to wait for a few minutes after the event starts then it lets me in
also randomly happens in PVP too
What’s happening is there is a small delay in joining the event. Force closing doesn’t really make it happen faster, I usually just choose the same time slice three times when it happens then I’m in.
In short- you’re seeing a visual bug due to minor delay in putting you in a slice.
You’ve had several posts in a row that state things about the behavior of the game as facts when you clearly do not have inside information of the mechanics.
The problem described in this thread happens erratically, the workaround given does in fact help, and simply selecting slices over and over very often results in nothing meaningful happening.
What I have is visible information of what is visibly happening. What you are doing is de-railing a thread by attacking another poster about things posted in other threads. If you’re not contributing with your own experience about this issue (which is basically a non-issue), then you’re actively hurting the forum.
You’re presenting your opinion and interpretation of your own limited experience as “what’s happening.” What’s happening for you may not be happening for others, so telling them good advice won’t help is what’s harmful.