Sample Loss In Android App When Retrieving Data Via BLE

I'm developing an Android app which retrieves data via BLE from a device in real-time.

As stated in the device's datasheet, BLE uses a 20-ms connection interval. Twenty user-data bytes (which is equal to 2- samples for each channel and 2-bytes running counter) are sent in GATT notifications. Data from the device is ping-pong buffered and up to six BLE-notification packets are sent every 14 ms based on an OSAL timer. The sample rate is set as 160 samples/sec. Each sample is 3 bytes and is sending 3 channels.

Each notification packet consists of 20 bytes containing the following:

Measurement Sample1 (Raw ADC data)
- Channel1 (3 bytes)
- Channel2 (3 bytes)
- Channel3 (3 bytes)

Measurement Sample 2 (Raw ADC data)
- Channel1 (3 bytes)
- Channel2 (3 bytes)
- Channel3 (3 bytes)

Afterwards I plot this data, but it looks like that I am only getting a sample rate around 105, while there should be 160 samples/sec. It just looks like some samples are missing looking from the signal.

I was wondering what could be the cause for that, is there a bug or a design flaw in the code? Are there any alternative methods to retrieve the data?

Here's a code that I use: codepaste.net/gqqgab