I have a pair of ASAs 5515x in transparent mode running active standby, similar to attached diagram, bridging multiple vlans.
They have been running 9.1 (2) and I upgraded to 9.5 1 following the proper procedure on Cisco.com. There were then reports of random application drops from one application (SAP). It started becoming more and more frequent and isolated to the site I don the upgrade on. No other applications seemed to be affected, Outlook etc.. The backend servers for SAP/Outlook are located in a remote DC.
I rolled back the Image to 9.1(2) and then the problems seemed to stop. I thought maybe IOS bug, although nothing related to this on Cisco site. I then tried today to use 9.4.1, and soon the same application issues arose. I removed the policy to stop sending copy of traffic to the IPS Sensor, to see if this made any difference but hasn't seemed to. Reason for upgrading is to support firepower services, otherwise I'd just leave it.