Android Question bt keep alive

Which problem did you encounter (what are you trying to solve)?

Oh, sometimes the bluetooth messages are a bit lagging. Click on sending just little pieces of data over the bluetooth connection, and shows up a bit later.

It might be your application. I have an application that interfaces with an embedded controller over BT at 115.2 Kbaud. Key actions on android device sends command, the embedded system replies with text strings for plots and numeric updates. All happens reliably and quickly. Typically command response under 50mS, seems good for human interface.