On sync, 2 calenders present and viewable , 2 "present" but not displaying

[Exomancer]

I synced 4 calenders between my phone and tablet. 2 synced fine, 2 did not. I checked the sync on 3 different calender apps to check. Syncthjng is working perfectly for many other files between the same devices. The file numbers and size of the files in the DecSync folders are the same on both devices. What could be wrong that 2 of the calenders don't display in the calender apps?