The point is that the FX market at the retail level is way too fragmented, so when you register with a broker you are not competing in the WHOLE market you are just competing with other customers that registered with that specific broker. Hence price movements on the wholesale level are not reflected on the retail level among all brokers equally. the euro/$ could drop by 20 pips on the wholesale level and it will drop on your broker screen by only 10 pips and on another broker by 14 pips
maybe because you do not know what is going on and not me making things up.....think about this (1)-get price feed from any of the wholesalers i.e. hotspot and compare the quotes live with what you see on your screen through your retail broker. (2)- compare quotes between any two retail Fx brokers for any currency pairs and tell if they are identical? In short in the retail FX market there no equivalent to the NBBO (national best bid and offer) you are at the mercy of your broker and the quotes you get are his not NBBO.
All am i saying next time when you see some broker being off the market by 10 pips like you said then you should do some screen recording and put it on youtube.