'Game Center' keeps asking me to sign in again on iOS

This is reproducible and not specific to SWGOH. I have never had problems switching Game Center accounts to switch between SWGOH accounts. However, this past week I started to see the issue described above with iPhone 6s iOS 11.4.1 the game app requires me to login into GC even though I appear to be logged in settings. Today I was in sith raid, switched to second app to answer text, and when I switched back to SWGOH I was required to log into GC. As I said, this issue is not specific to SWGOH; I also have the same problem when playing Onmyoji which also just started this week.