Hi,
I have got that sometimes with some cables, but not all of them. I often use different USB cables, depending on where I am, and one (no brand, no info on the cable) often makes the phone unusable while charging (but I usually can bring it to life when I unplug it, sometimes I also have to push the power button off and on), as opposed to another one which never causes problems (brand huawei, no info on the cable). The cable from a Samsung G3 does not work very well either.
You can find here some information on chargers here:
https://support.fairphone.com/hc/en-us/articles/207891033
And a list of chargers compatible with the FP2:
Not that not only the charger but also the cable make a difference. I my case, the same charger with a different cable behaves differently. It is possible that using a data cable makes a difference.