The Drips._isOrdered function compares two given receivers. The receiver config can include the prefixed dripId in the 32 most significant bits. This allows using the dripId for changing the order of receivers when setting a new drips configuration without violating the sorting requirement, First compares their amtPerSecs, then their starts and then their durations (see Drips.sol#L93).
While no harmful effects are expected, it can be used in the Drips._setDrips function to control if delta amounts of receivers are first removed, added, or updated, are expected.
Drips.sol#L1069
Consider omitting the dripId from the receiver config when comparing the receivers.
