Low Latency Mode is not for general use, it will not magically reduce latency most of the time and is used only during recording, You might try increasing the System I/O buffer to 128 or 256.
Low latency mode disables certain DSP effects the use look-ahead technology. The multiband compressor is a good example. If a plug-in adds no latency nothing is changed. Is a plug-in is disabled the slot turns orange.
If you leave it on during playback and there are delay inducing plugins.....you won't hear the mix as intended.
Low Latency Mode checkbox and Limit slider: You need to select the Low Latency Mode checkbox in order to activate Low Latency mode and use the Limit slider. The Limit slider lets you determine a maximum amount of allowable delay that can be caused by plug-ins when Low Latency mode is enabled (by clicking the Low Latency Mode button on the Transport bar). In Low Latency mode, plug-ins are bypassed to ensure that all delays (across the entire signal flow of the current track) remain under the Limit slider value. This is useful when you want to play a software instrument with several latency-inducing plug-ins inserted in the channel.
Low Latency mode allows you to limit the maximum delay time caused by plug-ins. Plug-ins will be bypassed to ensure that the maximum delay that can occur across the entire signal flow (of the current track) remains under the chosen value. The Low Latency mode is extremely useful when you need to play a software instrument (or to monitor through an audio channel) when plug-ins with high latencies are already in use—at any point in the signal flow for the selected track/channel.