I see Mar-April-May-Aug-Sept currently listed. The normal grouping is two front months followed by two at 3 month intervals aligned to one of three quarterly cycles.
It looks like CYN runs on Cycle 2 since the active sequence in the period before Feb expired was Feb-Mar-May-Aug. But in that case now it should be showing Mar-April-May-Aug. Why is there a Sept expiry listed at all? It does not add up...
Q-1 Q-2 Q-3 Q-4
Cycle 1 January April July October
Cycle 2 February May August November
Cycle 3 March June September December