make sure terrain graphics are maxed in settings.sometimes lowering those settings makes some of the smaller details (therefore possible shot blockers) not show.if the problem happens with maxed graphics,it may be glitches.send in support ticket with attached replay with description of glitch and at what time in replay that it happens.they have fixed some of these kinds of things before,but cant know of all possible problems unless someone alert sthem (ticket with replay),
if your graphics sliders for terrain rendering are not maxed,try to bump them to 100%. that may help.