First of all, what is latency?
It's the delay between an audio signal being sent and when you can hear it. You won't hear it when you're listening to music, but you might notice it while watching videos or playing games, as the sound is out of sync with the picture.
The same thing happens in BandLab - you might notice your recording being out of sync with the metronome or the previously recorded track.
Is there a way to fix it?
Sorry, but not at the moment. Latency is naturally expected with Bluetooth connections, so we do not recommend using Bluetooth devices for recording.
The typical audio latency occurring with wired headphones is around 5-10 ms. Bluetooth latency, on the other hand, can go anywhere from 34 ms up to 300 ms, depending on the devices you're using and what you're using them for. Recording audio in a multi-track environment like the Mix Editor, for example, requires significant processing power which can in return introduce some latency during recording or playback.
Nonetheless, there are a few things you can do to potentially minimize its severity:
Like humans, mobile and wireless Bluetooth devices need sufficient energy to perform tasks well. Fully charging them both ensures they have enough power to function as expected, but do keep in mind that the distance between them can affect performance too so make sure you're as close as possible to your phone when using the Mix Editor.