Intermittent white space in Graphs

Recently I purchased Enterprise edition. Initially I haven't hit with any issue. But all of sudden , there is some white space[ not plotting] on my graphs. Not sure what happened all of sudden. Even I updated the package with latest version. Though, Still its no luck.

Note : I couldn't notice any error in the log.

Moreover , I purchased this product to overcome my existing monitoring system which have less info compare to observium. But this unknown issues are too weird to me. Since My old monitoring system doesn't have any issue in plotting.