Timeline Error function of board use

Vince

Hello
i use different board  : 
for each of them i have a different view of timeline (not my need)
on one board the current sprint is not here (sprint 9)
on another board this is the closed sprint that are not present
     not all Issue in epic are show 
     i can not expand the epic althought there are issue in and in the current sprint
thanks for your help