F5 Sending resets

Hi can someone please tell me what causes this, cant find any reference to this:

this is being sent from the F5 to the client/requestor IP and breaking a lot of connections intermittently, its working about 60% of the time and fials the other 40%

RST cause: [29068a1:5584] {peer} SSL proxy shutdown
Length: 27
0000 000. = Version: 0 (0x00)
.... ...1 = Peer: 1
Value: 0x0000029068a1
Line: 5584
Cause: SSL proxy shutdown

Its just a normal virtual server running on 443 and the backend server is unecrypted on port 80 (not apm)