FPS IconįPS or Update rate icon appears when your frame rate is dropping or is unstable and the number of packets sent by your game client to the server is not high enough. The probability of experiencing those situations is far higher when the red icon is visible. When this icon is triggered, you can experience rubber banding, hits being rejected by the game server, and abnormal induced latency. The connection icon appears when you are experiencing packet loss or latency instability (for example, when some of your packets are being redirected on another internet route). When the latency red icon is visible, almost all of your hits will be rejected by the server. Being in that state for a long time could result in player being kicked from the game server. A red icon means your ping is bad (around 400-500 ms of ping).
Having a high ping also means you could encounter unpleasant situations such as dying behind cover. You might notice some of your hits are not registering. These additional validation steps come into play when treating your shots, and determining whether or not they are a hit.
A yellow latency icon means your ping is high enough for additional validation steps to be triggered by the server (around 100-140 ms of ping).