LoS and spells

[Anxarcule]

I play a non-twinked Monk and am not having much success at PvP against casters; recently I was jumped by the Druid ring in Feerot by a red druid and although I survived I found to my surprise that I couldn't hide behind objects to break line of sight on his spells.

I played Tallon Zek back in the day and I recall being able to break LoS by hiding behind objects - is this not the case here?