Double ALL global connections and database size for cluster on chart

[MirekWa]

I have strange charts with pgcluu (CGI) - sometimes global connections and database sizes for Cluster is doubled for All (see below pictures for example - the orange line is ALL - sum of all data). In moment it gets x2, few hours, then go back to good value. It looks like it's done in the same moments (but not always - see first part of charts). I don't know what's wrong.