New to DSP and having trouble filtering data
You should try with implementing your own linear filter. It is not really difficult, and you will have more control about what's going on behind the scene and it will make it easier for you to tune the filter bandwidth.
Speaking of bandwidth, you can try to plot the frequency analysis of your data using Fourier transform, that will help you in finding a suitable cutoff frequency.
A linear filter implements the equations $\sum_{i=1}^n a_i y[i] = \sum_{j=1}^m b_i x[i]$. As long as you normalize the weights $(a_i), (b_i)$ to sum to 1, you should preserve the range of the data.