Ring Group

Have a strange thing what happens

1: Internal extensions are calling a Misc Application number 

2: Misc Applicaction destination is Time Conditions

3: Time Conditions checks Match ok or non Match

4: Both matches go to a ring group with 2 extensions 

What happens is silence some times, you can make 10 calls without any problem. Then suddenly only thing what happens is Silence and if you wait long enough 1 or 2 minutes it starts ringing again. 

External calls also arives at the time conditions, there we have no issues.

I changed a lot of group settings, with parallel, Audio, ring, Announcement nothing helps so far

Direct internal calls works perfect, only group calls goes wrong

Hope somenone can point me in the right direction.